One of my CB250K0's needs the bottom tube replacing. I could weld up the holes but I would rather do a proper job and TIG weld a new tube into it, as we have the bending gear at work and it's not a complicated shape anyway. A member on HondaTwins.net (& also on here) suggested Reynolds 531 tubing. Anyone know where to buy frame tubing? I will measure the OD/wall thickness.