Years ago a local shop had a 20ga and a .410 thusly engraved (etched), so they definitely do exist. I actually wanted them but I was even more broke than I usually am at the time.

Regarding the 12ga, older is better with the B's, but Geo's $350 price is spot on. I recently sold a near-mint one that dated from 1961 at exactly that. Tried my darndest to get $400 but couldn't do it.

The difference between genius and stupidity is that genius has its limits. - Albert Einstein