I came across this knife in an LGS that is liquidating the estate of a prolific shooter.
It was in a misc. box with a bunch of assorted, mostly worthless leather items.
Took one look and had to have it. $10.00.
Appears to be a custom made knife. I believe the scales are antler or stag. the blade is Damascus steel.
Obviously the steel is a mess. so I am hoping someone will know the proper and safe way to clean and restore the blade.
I cannot find a maker's mark on it anywhere but it seems very well made. I would have preferred a lock blade but for $10 I aint complaining.

The right side of the blade looks like it has started to have been eaten away.
That may be from what is (was) a common way to bring out the damascus pattern. That being to soak the finished polished blade in acid,,usually hydrochloric.

That acid treatment would work on the iron & steel composition of the blade in different ways. Slightly faster on the iron and slower on the steel in the damascus so that the pattern emerges in view w/a 3D etched look..

What sometimes occures is that the damascus steel blade itself is not homogenous (right word?) and there are tiny micro cavities within the overlapping iron/steel folds that make up any of these damascus/laminated steels.
The same can happen with laminated steel/damascus bbls made this way. They can get looking the same.

Those 'spongy' areas in the bladematr'l hold some of the acid used in the process to bring out the pattern and if not neutralized they can continue to eat away at the metal.

This might be what has happened here.

It could be that some of the 'iron' portions of the damascus make up have started to rust and continued to.

The blade can be saved.
I would dismount it from the handle.
Soak it in a neutralizing soln for a good amt of time.

Then the blade can be re-ground to clean up most everything there I believe.

To put a Damascus pattern back in place (it will just be brite steel when re-polished),,I would use a rust blue and etch with Ferric Chloride soln to bring the pattern back out.
Same thing as used on Damascus shotgun bbls.
It won't give you that deep etched surface that a straight acid does, but it won't get you back into the same problem again either.

You could just try to clean it up using oil to stop the rusting and see if that does it. Oil generaly has little effect at neutralizing any acid though if it's there.

Don't scrubb too hard and you can save the B&W pattern that is there. The etched 3D will be there regardless unless you start polishing with grit cloth/belts to remove stuff.

Nice looking knife,,deserves some attention.
That's my take on it.

There are some real knife makers here. They can likely add real expertise to the discussion.

2152hq, would it be detrimental to soak the blade in a high PH solution?
Have no idea just thought that would counteract the acid but have no idea what the reaction of the metal would be.
Think I will wait and see what else is offered for advice.