Guitar Age like a Fine Wine.
I don't know about you, but you shouldn't worry about the finish aging, I think that it would be cool to have the finsh yellow. I take care of my guitars, but they still manage to age and such which is probably why I like them. I know on my JEM7DBK the tremelo is perfectly set (It takes a lot of work tog etit out of tune-other than when you restring it) and it feels so smooth. The neck has a weird caoting in it, and it keeps getting slicker-something that I like.
Just to let you know that you shouldn't worry about anything, if I was to buy a used 7v it wouldn't matter to me what color the finish was as long as the guitar itself was kept in good shape.