You're quite welcome. I've bought several used basses with scratched pickguards that I was able to improve with sandpaper. The bass I described earlier was actually NOS and the PG didn't have a scratch on it, but the little white oval in the middle of all that yellow looked horrible, so I figured I couldn't make it any worse.
I'm happy to report that I have yet to destroy a PG by sanding it. For me, losing a little material off the top is preferable to buying a new PG, especially since I tend to buy low to mid-priced out-of-production basses that would require having a new one specially made.