Rob,
I built that tank a couple of years ago but not with that POS Harbor Freight planishing hammer. It was on the bike until I had a little wreck with the bike lift. Built a polished aluminum tank with a Monza cap to replace it . Heres the thread when I built the first one.
http://www.honda305.com/forums/viewtopi ... highlight=
I didn't pursue the project as the welding became way too labor intensive and costly to get the guys here at the shop to do the work.
I've still got a bunch of the parts sitting around though.
Mark