Time once again to look at the differences between original Marvel Comics covers and the reprint books they later made a re-appearance in!
First up, we have Avengers #51 and the reprint in Marvel Triple Action #43. As you can see, the larger logo for MTA required things to be reduced a bit in order to fit! Heck, even the blurb on the bottom got replaced with a new blurb moved to below the corner box (which is, to be fair, smaller than the original had it). It appears that either the lettering was reused from the old blurb, or (more likely?) the lettering was redone in the same style. Also, note that Hawkeye's right arm is completely redrawn, as well as other parts of him (I notice his breechcloth is slightly different in the reprint). It looks like new art was done for the background on the top, and the machinery on the right got added to.
What happens when the trade dress of a comic is no longe rin style when the book is reprinted? Well, this happens... the art gets enlarged slightly, although mostly it's a case of it being added to on the sides a bit to accommodate the lack of a frame. If you look carefully, you'll notice the crowd of men fighting is actually overlapping Spidey a bit more than on the original, probably due to the larger logo on Marvel Tales #91. Note also that the background on the left is slightly different on Amazing Spider-Man #112... actually it's completely different! Changes were made on the left side as well. Also, note that while the "Cops Out" text is pretty much used as is, a new "Spidey" was lettered!
Not a lot of changes were made when Fantastic Four #22 was reprinted in Marvel Collectors' Item Classics #16... the Mole Man's speech balloon was replaced with the blurb for the other features in the reprint book, and the bottom blurb is also replaced. You'll note a new arrow blurb on the top, much smaller than the original, as well as a different blurb above Reed's head (the new blurb is even behind his head a bit). Finally, the background has been altered on the top and right sides. I've got to say, I definitely prefer the original coloring, too!
This takes us to X-Men #26 and the reprint in issue #74. As I've discussed in this feature before, I've long theorized that Marvel did all-new covers for some of their reprint books in an attempt to keep them from looking like reprints, but instead all-new books (honestly, even when the original covers were used, it took me years before I realized the cool Lee-Kirby Fantastic Four stories in Marvel's Greatest Comics were reprints!). In this instance, we have one of those rare situations where the new cover (obviously by Gil Kane) was much better than the original, which lacked dynamism.
We started with Avengers and Marvel Triple Action, and now we end there... when Marvel reprinted Avengers #35 in Marvel Triple Action #27, they did an all-new cover, although this was a bit beyond when they'd typically do that. My best guess is that the original cover just didn't work for the much larger logo on the reprint -- I mean, look at that thing! It's a third of the freaking cover!