Hey moonweasel - no problem, my pleasure. I started off as a guitarist as well and got sucked into the drum world... never really looked back (neither does my guitarist, but that's a personal issue) Ha!
Is till have my prized guitars, some of which are now vintage, and you're absolutely right... you DO NOT touch those finishes. A thing to remember - bass drum hoops are okay to refinish and not hurt value - shells are a different story, treat them as you would your guitar. Same applies, refinish your shells and they are still nice drums, but no longer original, so the value takes a hit... same goes for extra holes and adding extra hardware (like your mount there)... kinda like routing out a Les Paul Deluxe for a full sized humbucker guitar3 ...or in the case of your mount, more like routing the same Les Paul for a floyd rose DOH ...okay, maybe not that bad.
Nonetheless, if by chance or whatever, you started off with a really great kit in terms of the shells, sizes and desirability - good work! Keep us posted with pictures so we can follow along.
Oh, and yes... Ambs and Emps are Remo Ambassadors and Emperors respectively. Evans has their G1 and G2 series as their comparable models. Either brand will do you just fine, but Remo seems to be the head of choice among the vintage circles. I use both.