Well I know what your talking about. Its a 1978-1979 YZ 80 gas tank. Another one you can look at is a 1975 DT400. I got this 181 page TW custom book when I went home for Christmas. It had it in there but I bet they still modified the flakes one. Its not hard to modify though. You can take your stock TW tank and get a vintage tank. Take it to a metal shop. They will cut some 2inch pipe and weld it on the tank and your done. Get it painted. Post some pictures of what your aiming for. I got lots of ideas and if you have any questions I can tell you what I did to mine. I have one of those "hollow" bikes. They call it a naked bike in Japan cause you strip it down to the bear minimal like a girl.