Moto Guzzi 750 Ambassador 850 Eldorado Fuel Gas Cap NEW

So far as I know, this cap should fit most Guzzi models, single or twin, until the Tonti frames, so long as your filler spout has the recess for the mounting ring.

The cap is a beauty, absolutely rust-free and the rubber is nice and pliable.  It's almost too pretty to use.  It will likely fit lots of other Italian models, but the narrow part of your gas cap opening must be less than 44mm, according to my research.  The later caps with the lettering have a wider tang for those tanks and are quite a bit more common.