I've attached some new pictures so you can see what I'll be working with. The pic of the edge is closer to the true color of the board than the other two.
What I didn't write last time was that I was going to try the three solvents that I have in my shop, mineral spirits, alcohol and acetone to see if any of those do anything. If not, then I was going to sand to see if I could get to bare wood. If so, it's some kind of film finish but my guess is, it isn't. I don't have a heat gun so I hadn't even thought of that. As a last resort I'll buy some furniture stripper like the ones Stick suggested.
I don't have time to try any of this today since I'm headed out of town early tomorrow (Thursday) AM, to visit some grandkids in Boston, and won't be back until next week. I'll work on it then and let you know what happens. If none of that works, I'll be looking for the next approach.
Thanks for your help. This is a totally new learning experience for me. For the last 12 years that I've been woodworking as a hobby I've always worked with raw lumber, starting with the big box junk and graduating to a real lumber yard where I can buy lumber and mill it myself. I get a kick out of face planing a board and seeing the grain and figure appear. I was planning on buying a rough cut slab for the bench but when my wife and I went to a warehouse full of second hand furniture and reclaimed lumber we fell in love with this board. I so don't want to screw this one up,.