Once again, it's time to compare covers of Marvel Comics, the original comic plus the reprint book it also appeared in! Let's get started:
First up, we have Amazing Spider-Man #96 and the reprint in Marvel Tales #77. Now, this one is a tricky one, because as you can see, the original cover had that bar on the left side, which is gone for the reprint cover. Was a stat of the original art used for this reprint? There've been a number of alterations made, either way. Either the original art stat was used to provide the art on the left side not covered, or new art was added. Also, the word balloon has been completely changed (completely changing the meaning of the cover), and the burst has been replaced with the "Starring: Spider-Man!" panel. Most notably, the building Spidey is on has been shifted to the right, with more added between it and the building across the street. It's also been shifted up a little bit. I guess the new panel wouldn't have worked with this layout
Not much of a difference between the original cover of Fantastic Four #110 and the reprint in Marvel's Greatest Comics #98... except that the whole portal to the Negative Zone and the multiple Reeds have been shifted, with a new Reed figure (well, one of the original ones) moved over to just above Agatha Harkness' head. Several Reed figures were removed to accommodate the FF logo being used for the reprint issue.
Next, it's X-Men #29 and the reprint in issue #77... a brand-new cover to fit the current trade design Marvel was using, and a completely different scene, to boot! Gone is the Mimic entirely, and instead the Super-Adaptoid is fighting the X-Men, who were but onlookers at the edge of the cover before.
Next, it's Incredible Hulk #119 and the reprint in Marvel Super-Heroes #72! There's been so much altered here I'm amazed an all-new cover wasn't done. First of all, the Hulk's head has been altered, possibly just rotated. Then a ball was added to the chain, while the original end of the chain with a ball has been removed. The whole scene was reduced to make room for the UPC code. Maximus, on the other hand, seems to have been extensively reworked! I think the head and arms were just moved, while the rest of his body was completely redrawn. And of course, the blurb has been moved, too. As I noted, with all the cutting, pasting, and new art added, it seems it would've been better to just redraw the whole darn thing! Either that, or just reduce the image to make room for the UPC, and add some art as needed. That would've been simpler.
Finally, we have Amazing Spider-Man #84 and the reprint in Marvel Tales #65. Here, we've got a case where the Spidey figure was moved down, making it necessary to rework some of the background. Again, I'd think it would've been simpler to reduce the whole image just enough to clear the logo, and maybe use a smaller Spidey figure in the corner.