Thanks all for the thoughts.

One reason I wanted to use a printed template is that I am building my first fillet frame without using a jig. I am counting 100% on exact miters to get things lined up properly. Scribing with lugs would be ideal, but I don't have lugs!

All this being said.....

I used the template spit out by that spreadsheet above yesterday and it was pretty much spot on with just a tiny amount of fine tuning. Finished up my front triangle and it came out surprisingly straight considering I have all manner of wacky sh$t going on to hold the tubes together for me (random chunks of angle iron, c-clamps, cable and weights, etc.) for brazing.

Thanks again!