I'm sure FLLMNTY stands for The Full Monty, yes, referring to it being somewhwat powerful I'm sure..
So Wayne B has identified the right car and gets the point. Although various sites picture the car and quote different information it would appear that this is a 1956 car with a 1976 V12 engine.
But I really don't know if that is its name or if they are just quoting its registration number; no other site quotes a name..