The plot is pretty simple, in the year 1959, Nick Fury calls together several heroes of World War II and emerging heroes to fight Nazi war criminals. And the story has an interesting mix of historical comic characters and later ones re-conned into the past. More modern creations like Sabertooth and Kraven the Hunter rub shoulders with Golden Age characters like Namora and the Blond Phantom. Two characters from an earlier story, Bloodstone and Silver Sable (father of the current one) also show up briefly. Plus we get Chaykin's own creation Dominic Fortune.
It was supposed to have a Mad Men meets Marvel kind of vibe but really falls flat. At times this feels like a wikipedia article turned into a comic as obscure villain after obscure villain turns up offering nothing but a name and a costume before being duly punched, shot or stabbed. We get Baron Blood and Brain Drain, a Nazi vampire and Nazi robot respectively. Later we get a whole team of Nazi villainesses who, I assume are obscure characters from WWII comics. Finally we get a whole army of Nazi supervillains! But none of them, not one, manage to do anything interesting or have enough screen time to be anything but generic baddies.
And the 1959 Avengers aren't much better, too many of them have the same voice, the same personality and even the same face. All in all this book is too thin, too crowded with obscure characters and too reliant on readers caring who the characters are from prior books. Perhaps if the first Avengers 1959 story had been included or if some more background had been thrown in it might have worked better but as it is this book is just not that interesting.