I learned a great deal about the older MV singles when I overhauled his engine and electrical system. Easy to work on, but there are NO service manuals. Also discovered the parts catalogs are not always exact. I would look at several different manuals to confirm information.
Bearings and seals for the engine are readily available, but by using bearing numbers and seal dimensions, not MV part numbers.
eBay Italy is a good source for parts, and the original clutch plate manufacturer still offers OEM clutch plates. Seat covers and such are easy to fine.
Barber Vintage Festival at the Barber Museum first weekend of October.....
What parts do you think you need? Engine is obviously apart but the rest looks quite complete. And what advice are you looking for?
Having built 3 of these engines, and with yours all apart I would recommend you do all the best things for it; crank rebuild w/upgraded bearing, modern piston (which could mean a resleeve), and electronic ignition. Doesn't seem like much but always takes longer than you'd expect. I also recommend those FaceBook groups mentioned for help and parts.
I'm also in NorCal. Cheers.