Skeet,
I have a New Hermes TX model. It has the motor for cut engraving, and the diamond tipped doo-dad for doing scratch engraving. I use the scratch engraver on barrels. I am quite happy with it as it does a nice job and is easy to use.
I paid the princely sum of $0.00 for mine, 4 sets of fonts, cutters, attachments, etc. My machine shop owning friend had it, didn't use it, and was tired of it cluttering up his shop so I reduced it to possession. I did give him a couple cases of beer, though...
As they are old school technology, you should be able to find one at a decent price. Until then, heed the advice given above and find a local trophy shop. In my pre-pantograph days, I had a trophy shop do a barrel for me. It cost me a whole 15 bucks.
Attached are a few pics. A barrel I engraved this past weekend, and a set of vee blocks I machined to hold barrels whilst engraving.
Justin