Pantah F1 camshaft identification

[chipper]

Does anyone know how to decode the markings stamped onto the lobes of older Ducati cams?
I bought a bunch of parts 'in a basket' and the cams aren't identified. I expect the 'O' and 'V' are 'Orizzontale' and 'Verticale' for horizontal and vertical cylinders, but most of them have another letter stamped. I have, OR, VR, PV, PO, EO, MV, and some stamped just O and V with 3 holes drilled in one lobe.
Any clues would help a lot.