Spots on blades? One of the reasons that I don't purchase straight carbon blades anymore. Spots is rust or staining....not acceptable on a knife that I wish to collect.
10+ years old? A drop in the bucket....already have knives that are 25 years old, purchased new from the makers....pristine.
The idea of "honest aging" is something akin to sentimentality in collecting...."oh look it's got patina, that's worth something, right?".....uh no, it isn't. The slipjoint crowd likes that stuff, but not usually in custom knives....they are a nutso group anyway, collecting things like elephant toenails....that's just retarded...really, I'm not joking....let's go out of our way to collect the ugliest folding knife pattern ever created.
That aside, do what you want, collect what you want, it is your money and time.....BUT....at some time, down the line, when something needs to be moved, the market tends to look at things through the lens of "perfect condition is desireable" and not "Grandpa's pocketworn knife sure is swell and I want to buy it".
Best Regards,
STeven Garsson