www.925-1000.com

Marked as J.H. & A. Benedict

The other marks are however odd. An American eagle, followed by a D and George III duty mark.

Any opinions would be helpful.

They don't mean anything. They are pseudo hallmarks meant to give the impression that they are hallmarks. If they mean anything it is the eagle is American, the D stands for Dollar or Coin, etc. They are quite common on late coin silver usually around the NY area.
Maurice