So is that how the originals were made as well - silk screening?
As for painting the barrels biffta - I had the same problem with degree of gloss. The third time i did it, I was happy with the result. I used Dupli Color Engine Enamel (with ceramic). The colour code was (and probably still is) CDE 1634/GM Chrysler Black. If you're interested, be careful though - that number, like a lot of stuff - may have a different number from the US number (for up here in The Great White North.)
IMHO it's a perfect black for the gauges - not too glossy and not so flat that walking close by scratches it.
Cheers,
wz