That is good info, thanks.
Yes, Heidenau's do look good.
But the rear tire is an issue. And having gear on the back will obviously add to the problem. I'd like to solve that without going into modding, given that's a slippery course in itself.
Apropos, I followed the build of your trial. Wasn't an easy task, -I still feel a pang at the thought of that poor engine-, but brought to an excellent result.