1913 S Type 2 Buffalo Acid Treated?

I agree with 52Raymo.. My guess is a ground find that was vinegar soaked to clean it and then artificially toned. Get a few no date Buffalo nickels, soak them in vinegar for a month or so and you get a very similar look.

With regard to the question of whether it's been restored: I doubt it, and if it was, it was then polished\whizzed to remove the dullness. Whether it was or wasn't, this much is true: It didn't need to be. Restoring "restores" lost detail. This nickel still had plenty of detail including, most importantly, the date. I'm thinking that at some point in its life its obverse was flush up against something very smooth (and possibly metallic) with moisture and minerals present between the two. The reverse fared much better for reasons unknown - possibly because it was up against a much lighter, or porous substance...or just air.

I guess it could auction for more than $150. Heck, I've auctioned restorations of this date and received more than $150 for them, so why not? I just always figured that crazy stuff like that was because of the full moon.

***edited for punctuation***

I had an 13-S T2 that I nic a dated. I put it out in the case with a $100 price tag and it sold within 3 days. So I'm in agreement that $5 to $50 it way low.