+1 on that frame repair Terry. I'd like to know more about the splitting the tank idea. I have a few that could use it.
Thanks Dave, Danny and Fred et al, on the older CB750 tanks (and maybe the 500 tanks too Dave) the top and bottom sections of the tank are seam welded, so I used the linisher (belt sander) attachment that's mounted on my old bench grinder to carefully grind around the seam, just enough until the seam started to split.
Once you've got the two halves apart it's a piece of cake to bash the dings out. (don't be too over-enthusiastic with the hammer or you'll end up with a high spot which you'll need to shrink back) Once you're happy with your panel beating efforts, just braze or Tig weld (not Mig) the two halves back together again.
Make sure you do a leak test though, or buy a gallon of POR-15! I did post some pics on this thread from memory, back in November or December last year, I did that tank on my blue K2. (December BOTM winner) I've got pics somewhere, so if you can't find my pics on this thread, I'll dig 'em out again. Cheers, Terry.