I searched and read a number of threads about these. My 3-key car is missing the gas cap AND the two small keys. The keys are on the way from MB classic. I have read that that the new 3-key style gas caps cannot be keyed to the original car keys, and I've read where some guys got it accomplished at a locksmith.
I don't really mind having a 4th key that will come with my new gas cap, what I would like to know is if the key on the reproduction gas caps can be removed from the cap in the unlocked position? A lot of locking caps from this era HOLD the key into the lock while the cap is in the UNLOCKED position, requiring you to LOCK your cap to extract the key, and UNLOCK your cap everytime you want to get gas. I haven't heard of anyone stealing gasoline in about 40 years so even if I had a locking cap I would never lock it.
I like the looks of the locking caps, and I specifically do not like the looks of the OE NON-locking caps with the big rib on it. If I can get the key out of the locking cap while it remains unlocked that's what I'll get (not really caring about the 4th key thing)
Thanks everyone!