Rust Patina

Is the tarnish on my knife blade good or bad for value?

I have a very old combat knife that was given to me after my grandfather died. It has a 4-5 inch blade on it, made of steel. The handle is all metal, with a compass on the rear that screws off the reveal a secret compartment for survival equipment such as matches and other things. The blade itself has obvious signs of heavy use, but the blade is still in good condition and it’s sharp. It has tiny bits of rust, and a unique patina to it that it got from several years of use in the field with the military. I’m trying to get the maximum value out of this knife so that I can keep it and hopefully give it to my grandson one day. Is the patine good or bad for value? Should I clean it off or keep it on? I’ve heard answers on both points of view on this, and I need some closure on the subject. Thanks!
correction, *patina

Its very good for value, the amount of tarnish can help determine the age of it and if its what you say it is. I would take it to a pawn shop they wont pay the auction price but they will give you something fairly close.

Knives And Rust Good Patina, Bad Red Rust