You should see if he's interested in buying it back before you sell it on ebay, being it was his dad's and all.
Considering I got it off of him for $6, and have all of $1 in the resto (can of Industrial spray paint that I scored at a local fleemarket last weeekend

) I'd probably insult him for what I think it's worth.
The guy was really cool. I'd say he was in his later fifties and had that Mick Jagger sway about him without the money and fame. Anyway, he goes to old farms all around Delaware since he dad was well connected with the farming community and digs up all sorts of cool old farming implements, glass jugs/bottles and some other strange and unusual things he stumples upon. He said he's been doing it since he was about 8 years old.
The day I purchased the vise I saw him setting up his yardsale early in the morning while I was on my way to an auction house I go to every other Saturday. He had TONS (I'm talking around 200-300 pieces) of old glass medicine bottles, milk jugs, mason jars etc. on several large benches in his driveway. When I passed it later on my way home every bench was completely empty except for the vise I bought and a smaller clamp vise he was keeping. I would have definitely bought some from him, but he said people were buying 20+ a shot since his prices were rediculously low. He said he was heading out the next day in search of more so hopefully I can get some pretty soon. I'll post some pics if I do.