Terry, curious if you have the aluminum 'base plate' (a custom detomaso part) and the steel boss that goes with it? If you need the latter I've heard that the same may be used on the mid 70s 308GT4 Dino...i.e., making new is probably best - see photo. If needed, height of the boss is 42.5mm, diameter is 23.2 mm, flange dia = 36.2mm. The stock Mangusta has two identical bosses. As for the pulley, my notes show "66 x 20mm", no idea where this part originates, unfortunately.