I've been reading through the crossover event called Silver Age which DC published in 2000. It was set during the Silver Age era of DC's history, and was surprisingly well researched. However, it is also written to fit into the post-crisis reality, so it has some continuity problems.

I liked it a lot (except for one egregious plot point, which I will mention) and so I started imagining how I would rewrite the story to fit into the actual Silver Age of DC comics

I absolutely do NOT mean to make this a part of Earth-1's official chronology. This is more of an experiment.

First, let me set the scene. This crossover must take place after Justice League of America #27 (because Agamemno mentions that this was when he observed the JLA in action) and before Justice League of America #31 (since Hawkman has not yet joined the Justice League). I lean toward the earlier end of this, so I'm assuming this takes place in (publication date) May 1964.

This is where most of the characters were at this point

Lex Luthor was last seen in prison in Action Comics #309. He would next appear in Action Comics #313, still in prison. For this story, he would have to escape at some point before the crossover, which is easy. He did it all the time. Of course, in the story Luthor is supposedly a legitimate businessman. However, this is easy to write out of the plot. The fact that Luthor is a legitimate businessman is only relevant to the issue Silver Age: Doom Patrol, and otherwise he is acting more like his old mad scientist self. I would have Superman be trying to find anti-superhero weapons at Luthor's old bases, when General Immortus and Garguax steal them, and he has to contact the Doom Patrol and try to convince them who he is. Also, the writers show the Injustice League operating from Luthor's museum base, but that base was already abandoned at this point. Luthor's current base would be the abandoned planetarium.

Superman is between Action Comics #311 and Superman #169

Dr. Light had had only two appearances by this point, since this is early in the Silver Age. In fact, this is true for most of the villains. Dr. Light last appeared in Atom #8, and would appear next in Green Lantern Vol. 2 #33

The Penguin had just returned from his temporary retirement in Batman #155. He would next appear in Batman #169

The Blackhawks are between #196 and #197. This is right before they transitioned to their new uniforms and tried to modernize

The Challengers of the Unknown are between issues #37 and #38. They have not yet transitioned to their new uniforms, so that part of the comic is inaccurate and would have to be changed.

Catwoman is interesting. She is in the gap period in her career (which I think Doc mentioned he has some ideas about) the Earth-1 versions of her golden age adventures have all happened (the last one being Detective Comics #211) but she has not yet had her first Silver Age appearance in Superman's Girl Friend Lois Lane #70. Her costume is of course totally wrong. She should be in the purple dress and green cape. Also, she is a tad too murderous in this adventure, toward the end. My theory is that she was getting a bit drunk on power

Elongated Man is between Detective Comics #327 and #328. He has abandoned the use of his mask by this point, so that would have to be corrected

The Doom Patrol is between issues #87 and #88

Sinestro is one of the few villains who have already had most of their Silver Age appearances. He last appeared in Green Lantern vol. 2 #18, and would not appear again until Green Lantern Vol. 2 #52. However, in that issue it is indicated that he spent most of that time trapped in the energy cube. For this story to work, he would have to escape from the cube early, and then be re-imprisoned in it again later

Hawkman had just gotten his own series at this point, and this adventure would take place between the two stories in Hawkman #1.

The presence of Mr. Element in this story is a huge anachronism. In the actual comics, Albert Desmond only used the alias of Mr. Element in his first appearance, and then switched to Dr. Alchemy. This is fine, since he also never used an Element Gun in the comics. I would change him to Dr. Alchemy, and his element gun into the Philosopher's Stone, which does in fact transmute matter. Dr. Alchemy, Felix Faust, and Chronos all appeared last as member oft he Crime Champions in Justice League of America #22. In fact, the Injustice League in this story is almost like a Crime Champions reunion with expanded membership. This makes sense, since actual supervillain teams were still rare at this point. Chronos appears next in Atom #13. Felix Faust appears next in Justice League of America #49. And Dr. Alchemy reformed after this point

Black Canary is in the story in place of Wonder Woman, to align it with JLA Year One. To fit it back into the actual silver age, I would change Black Canary back into  Wonder Woman, which would involve slightly re-writing a few fight scenes throughout the crossover

For Green Lantern, this is shortly before his first battle with the Black Hand. Like most of the JLA, he last appeared battling the entity called I. All the other Leaguers will appear next in another Justice League story, so I guess their hometowns are quite right now.

For the Teen Titans, this is right after they first teamed up, as described in their origin from Teen Titans #53. All of them (except Speedy, who we hear little about during this time) would next appear in Brave and the Bold #54. So the team is not an anachronism as I feared. They do exist, but only just barely, and are probably still getting organized.

The Metal Men are between Metal Men #7 and Brave and the Bold #55

Adam Strange is between Mystery in Space #91 and #92

OK, so much for the easy ones. Now come the complicated ones

Batgirl doesn't work for this story at all. This is before Barbara Gordon's debut. I would replace her in the narrative with Batwoman. Kathy Kane had last appeared in Detective Comics #325. She retired from crimfighting around this time, but even if she has already retired, it was very recently, and it would be easy to write her coming temporarily out of retirement for this one adventure

Black Manta had not yet had his first published appearance, which was in Aquaman #35. However, in that issue Aquaman calls Black Manta his "old enemy," which implies they have had a number of untold battles before this point. Therefore, I have no issue with Black Manta's presence in the story.

Of course, this is long before the debut of the Atomic Knight, but it's actually part of the narrative that this is long before he beings his actual career

This a few months before either Mento or Metamorpho debuted, so they would not be available. Neither of them are essential to the plot, so I would just write them out.

This is long before Deadman began his career, so he is also not available. However, he does play a key roll in the plot when he works with Adam Strange and Kid Flash to rescue the Green Lantern Corps. I think that Adam Strange and Kid Flash could have saved the Lanterns on their own, however, so this is a fixable problem.

The biggest problem is Robby Reed. He is essential to the plot, but this is a couple of years before his first appearance in the Silver Age. I think I would have to move his adventures back chronologically so that he could participate in the crossover. This would not cause a huge disruption, since his adventures have nearly no connection with the greater DC universe.

There are a few minor changes I would make to the plot. I didn't like the deus ex machina of Green Lantern's ring simply revealing the JLA's true identities. It's more fun if the villains have to struggle to try and figure it out for themselves. The idea that, by taking Green Arrow's body, Faust somehow gained his archery skills, or vice versa, is ridiculous. I would have Faust still use magic in Green Arrow's body, while GA recovers a new bow and quiver from the Arrowcave and struggles to use his arrows in Faust's body.

The BIGGEST re-write I would make is Batman's idea to try and convince the world that the JLA have gone evil, so that the villains will not use their reputations to conquer the world. This plan is stupid, convoluted, unlikely, and shortsighted. It is inconceivable to me that Batman would suggest it. I would cut it out of the entire story. Instead, the JLA will be racing around the world to try and find allies or resources to fight the Injustice League, while Penguin (in Batman's body) tries to head them off and convince the other heroes that the Injustice League are trying to trick them. This explanation can fix nearly every issue. The hardest one is Silver Age Dial H for Hero. Obviously, the Martian Manhunter will not be trying to frame himself by attacking an army base. Instead, I would make it that while Robby is on a school trip to the base, the army is notified by "Batman" that the Injustice League is on the loose. Robby uses the Dial and goes in search of the villains, running into J'onn (in Dr. Light's body) who is trying to make his way to his secret base to get help from Zook.