denisc That is a bummer . . . I have a pair of vents I pulled out of a Fiat 124 they are bigger (90mm dia.) and My goose are 75mm dia. and they have more louvers.
My goose vents have mounting studs broken off. They will lay in there holes and might look Ok . . . But when I get My car roadworthy and ever decide to ship it to Germany and run the Auto-bon "at speed" . . . they might blow out _Ha!
In photos below: Fiat 124 on Left, Mangusta on Right _Thanks