www.925-1000.com

Some of these seem vaguely familiar, but I don't know why. I didn't see any of the marks on the Hanau page, so maybe it isn't Hanau? But if so what is it?

These are not Hanau marks, it needs to be moved to French silver.
The first mark is a caduceus (upside down). a counter mark or discharge mark.
The second mark is Bordeaux 1783-4 date letter G.
The next mark is maker's mark for Charles Louis SEGAY b. 1735 master 1762
The last mark is no doubt a K which was the charge mark.
It would be nice if you cleaned out the marks with a soft brush or a softened wood toothpick
and a little silver polish. Then retake the photos, try to get diffuse lighting.
Finally if you give the name written out, I might be able to identify the owner.
I am curious what is the blob above the first mark?
Maurice

Thank you for your reply! I'll post better pictures shortly. The blob is where a previous owner scraped into the metal, apparently to determine whether it was plated or not. Luckily they didn't damage any of the hallmarks. More info soon.