Someone gave me a Yamaha XS650 Special II and as it turned-out, I knew the original owner. I soon had it running. It had a rusted-out gas tank. There was a used parts bike place in town, he had a 'difficult' reputation. I called him, and he said he had a gas tank for it. I went to the shop, and asked for it. He went in-back and came-out to the counter with a gas tank, he put it on the counter top and held onto it. I reached for it, to take a look, and he pulled it back. He wouldn't let-go of it. I finally told him, "hey I gotta inspect this, show me the other side!" I already noticed that the fuel petcock was removed, the tank emblems were removed, even the gas cap was removed! He turned it around, and I saw that apparently the bike had fallen onto that side in a 'while underway' accident. The tank was caved-in, and probably perforated, once I saw the crash damage, I wasn't interested anymore. Just-because I wanted to hear his story, I asked the price. He told me, and I asked, "are you gonna give me the petcock, the emblems, and the gas cap?"
"No," he replied, "those cost extra!"
What a piece of S_it that was! As he offered it, it was useless to me. If he gave it to me, free, I probably wouldn't have taken it.