All About Pocket Knives

This one is from my Father-in-law's collection....

I am guessing this is a fishing / fillet knife? I think it is a 121? Can anyone tell about when this one was made?

Thanks,
Unk

Hi:
It is an early fisherman. The scaling teeth were dropped mid 60's. It is a pinned flat tang model which started in 62. If the knife is original to the sheath with flap, they started in maybe 64. That using a bit of deduction would put your knife before they dropped the teeth in 65-66 era and after 62 when they went to flat tang and with the 64 era sheath would make your knife in my opinion about a 1964. Heck wouldn't it be something if it were July 17th, 1964 as that is the day I mustered out of the U.S. Navy.
moss

Edit: Joe should be around soon and straighten out any errors I made.