There is no question. The knife looked new before cutting the tomatos. It was just last evening.And yes, it was probably the 'maters. Remember the Romans thought tomatoes were poisonous because the acid would leach the lead out of the pewter plates, giving consumers lead poisoning.
Leather sheath? I ask because my combat knife I bought from Cold Steel in 1989 a Recon Tonto 7" blade Carbon V steel. It was American made at that time. It came with a leather sheath that I put on my ALICE web gear (Yes I'm getting old). Anyway I had to constantly oil the blade or it would rust. I believe my perspiration was somehow getting inside the sheath. I still have it but I store it outside the sheath if course. It has some serious sentiment value. The things I did with that knife....