Hi, first post...found a box of old kitchen knives and other utensils, the first one I picked up is a La Trompette marked 1878 M. Pouset France. It's 15-1/4" total, aprox. 10-1/4" blade and full tang. There are 5 "rivets in the handle, spaced 2-1-2. I tried searching for the exact style but don't see anything like it. It would be nice to know it's date and value. Also is it worth keeping/sharpening and using it or would that hurt it's value? Thanks