This is the second of 3 pieces I bought hoping they're Heintz, but since it's unsigned I'd like to find out how right or wrong I am. It has has "Pat App For 4536" stamped on the back. I know there were other makers who did similar style work.

This is also by Heintz. Much of the work is unsigned with their logo. Often these unsigned items will be marked sterling on the silver decoraion.
Fred