This may appeal to only a few fellow Nikonians, but allow me to take up a little space.
If you´ve just gotten a FM3A and you want to use it with a flashlight by the German manufacturer Metz, don´t hold your breath.
Metz has as yet been unable to obtain a FM3A and therefore can´t say which SCA-adaptor to use.
Anyway, Metz assured me that using the FM3A with their units isn´t a problem, the trigger voltages are too low to pose a danger to the body´s contacts. Simple TTL should work with most of the Nikon-type SCA-adaptors.
I´ll shoot some flash test pictures and add more soon.
... if it´s not in focus, call it art.