Still learning about some of the models and how to date the knives.

Last weekend I got these 2 knives and I think what I have is 25-5 and a 16-7? fighting knife?

I think these are from the 80s, could be wrong, the previous owner Bill Johnson bought these and engraved his name on them. He couldn't remember when he bought them. I personally don't mind someone else's name on these knives but does it hurt its collectability and value?