Thanks Bababooey. Of course it will sell, and I'd be surprised if it fetched anything less than $80, but you never know. I've listed five or six DB large cents (several 1798s and an 1802) over the past few weeks and all have done well, though this is the roughest example of the lot. (Still, $20 would be simply absurd, and I'd pay $60 for this in a heartbeat).
Amida is probably right -- this coin has spent some time in the ground.
Philadelphian -- the lettering and punch position sure seems like S-130. Still, I was wondering if it might be something else, like a 120b. Hard to judge with the corrosion, but it seems like it might be a "gripped edge", if I understand the term.