Bruce,
Spinotto in means in general pin, or yes in electornic jack or plug.
but in this case is gudgeon pin.
I've called "GANDINI INDUSTRIA SRL" and i spoke with the techincal service.
They have at the moment no pistons in stock, but they have still the castings so they can produce some if needed. Minimum order would be 10 per diameter.
They use shell casting as means of production,
and the alloy used is a low expansion 12% Silicon alluminium alloy. ISO code 48000, that should correspond to the british LM13.
the price advertised do not include VAT, but they can do a reduction if a consisten lot is ordered.
Coming back to the measures, i've asked clarifications so please if you go back to the table please read "Compressione" as the measure of the height in mm between the gudgeon pin centre and the pistons top circonference, the "quota" is the height between the piston top circonference and the top of the piston head dome. Hope is clear!
Edmondo