Building metal tanks

I my current vein of learning things that I couldn’t as a kid, I tried my first attempt at building a metal tank. All I got was cut up fingers.

I used thin KS brass, and some oak strips for bending.
I cut a tank form out of a fir 2x4 on my table saw, and tried to form the tank ends with a hammer. I could never get a good crisp edge. Does the form need to be metal? Also how much relief you need to cut in the corners? The brodak tanks seem to have almost none.

Also my tank bends were not quite accurate enough, and the thing was a mess, and I chucked the while thing.

A plastic tank will not work, this is a short nosed profile, and I want the tank on the outboard side. A square wedge style and about 2.5-2.75 oz. There is less than 3 inches between the motor to the LE.

I can solder well, but my metal working skills are not up to par.

Can you recommend tips and techniques that work? For tools I have woodworking tools + tinsnips and a file…

Is better to cad draw it and attach the pattern to the metal?

Thanks