I, too, am one of the "too many keys" group. My gas cap, though externally correct, has been replaced at some time, as it no longer matches the door key (and is a different key pattern). For the last 2 years, I have asked every seller of a correct cap on eBay whether their cap has a "TA" key, and so far haven't found one. (If anyone has a good TAxxx cap available [my door key is TA061], or wants to trade one for a good TB032 cap, let me know!)
-David Pease
'66 French 230SL