Theoretically, you should be able to get 2 brackets from the same piece of tubing, or is that not possible because of the difficulty separating them?
Also, for oval extremists interested in the maximum offset, how about brackets made from 1.5" tubing with the motor shaft and screw holes set as far to offset side as possible? The rest of the chassis could be pretty basic but the motor's weight would move the center of gravity as far to the inside as the width of the left rear tire allowed.
Lastly, I know all of us old skool slotters were raised on soldier and flux, but with 3D printing is anyone making similar motor brackets out of hard plastic? With epoxies like JB Weld hybrid chassis of brass & plastic would be fun to experiment with. I like the idea of being able to hold parts together with my fingers while the joints harden.
Slothead