"I got most of the bottom diagonals fit. I've been using my 6"" grinding wheel for most of the fish mouth cuts and I have a little Harbor Freight 3"" grinder that works great to fine tune the cut or get those high angle fish mouth cuts that are hard to get to on the bigger grinder.
One thing I find real helpful is before I start fitting the tube is I put a center line at each end to work from. Butting the tube up against my straight edge it's real easy to set a nice center line for reference."
