How funny, my first time ever on this site and saw your DePonceau pewter question. The DePonceau family lived right around the corner from our summer home in Chautauqua New York. The senior DePonceau who more than likely did your piece lived to be a very ripe old age and only passed on a few years ago.
Every piece is genuine handmade and thus none are exactly the same.
The family still owns the house and barn where his studio was. His work is quite collectable in that area, though I am unsure of how well known he was outside of the area. He was quite the artist and also a charming character! Sorry I can’t tell you value of your piece. A Chautauqua Antiques dealer (and there are many in neighboring Westfield NY could tell you though!):)