Coin Silver Spoon Unidentified

This is a large coin silver spoon I recently won at auction. It weighs 26 grams. The previous owner claims that it tested for coin silver. I do believe this after seeing it in person. When I bought this I thought it was American. Looks like I was wrong, maybe.

I have a feeling I know the maker of this spoon, but I am not 100% sure. To me the hallmark looks very very similar to a Hanau smith by the name of J.D. Schleissner.

I would like to see what others think here, please let me know what you think!!!

The hallmark in the third image is on the left side of the bowl, and the fourth image is on the right side of the bowl. Here is a clue, all hallmarks are on the underside of the bowl.

Later!!!