Thanks for really interesting feedback everyone. It seems that there are number of paths to choose from so I'll wait until I have my drum in my hot sweaty hands before deciding which to go with. I'll be sure to post before & afters fots if I decide to clean it.
Hey Gerard, I personally like the yellow look but if you try matching other drums it can be tricky. I have some off-cuts of Ludwig WMP that's quite yellowed. If you want some to experiment on I can send you a piece.