As 8b correctly states, original snapcaps were not engraved, they were stamped and I don't know anybody who offers that except Helston Gunsmiths in the UK who will stamp up their brass snapcaps if you buy enough!
We can get soft metal ones CNC engraved but, as you noted, they are not the same as the stamped ones. I think it a little unfair to say the 'quality' doesn't match, it is the depth and style that is different IMHO.
Snag is that most nickel or chrome plated snapcaps are made of steel and would need engraving or stamping before the plating process.
