I purchased a 1988 steel Italian bike with Miche hubs and a Suntour 6 speed freewheel- the 2 prong type. The wheels are rough when spinning on the axle so I am working on servicing the hubs. I am wondering where I might get replacement cones as they are rough, one is very damaged, the other 3 are slightly marked where the bearing are supposed to roll. The cups seem to be ok. The cones are standard 5/16" and 3/8". I have seen some unbranded on ebay. Are they all the same size-wise, i.e. the angle of the curve etc.
BTW I am based in Europe.

Wheels Mfg Hub Cones

This is the place, unless those miches have some weird cone shape.

Miche hubs from that era were usually Campy clones, but I found them to be among the worst in quality of the many Campy copies: really soft alloy shells and poor tolerances of the steel parts. If you can find Wheels Mrg. cones that match the dimensions and threading (and measure with an acurate digital caliper plus a thread gauge for the axle threading to be sure) that's going to be much better quality that the original cones, probably better than they deserve (yes I am biased). You might just wants to replace the full axle "set" with new axle/spacers/cones/nuts. Miche components these days are MUCH better quality, at least the ones I've seen and used.

Yes, they used the same 26tpi thread as Campy. But this also means you could use Campagnolo cones, which are high quality.