That is a nice-looking coin, and awful familiar-looking to boot - did it come out of the Heritage sale of the Kochel collection last year? He had a ton of errors, mostly low-grade, cleaned, and/or corroded. Oh, and Matt's right, it is C2. !797s and 1795s are often stuck on TAL tokens, or spoiled large cents. Look at the edge lettering, I've seen at least one where the lettering was the only indicator of the undertype - it even allowed identification of the specific year of the TAL used. Visible undertype does justify some premium, with the amount being dependant on the amount and aesthetics, as well as the coin itself. I myself don't own a piece with visible undertype, but would be happy with a piece like that. Nice coin.