I had a closer look at the TC design and it looks pretty practical to me. They don't have an outboard bearing support on the rear crank projection, it is cantilevered off the cases from the look of it. They use the big aluminum tube as a bearing carrier for an inner shaft that carries the prop hub at the front and the driven sheave on the back. The only thing I would change would be to swap a toothed belt for the double V setup. Copying their general layout and system will get you in the ballpark without too much trouble, I would think.

If you plan on paying someone to make all these pieces, be aware it will likely cost more than the TC one. If you have a machinist buddy or can do it yourself, then it is a much more reasonable plan.

Mark