I bought replacement buttons from Marco on a Slugfest I did some work on recently and they all fit fine and worked/looked great. Looked the same that was in there? The only one I didn' tlike was the player two button, the little men were not centred on the insert.
As far as the removal of the CPO, like dirtbag66 said, quite a pain but with GooGone I got it cleaned up pretty well, actually used a metal paint scrapper along with googone.