Got hubs back from vapor blasting. I decided to have the R90 hub converted to standard sealed bearings by Woody's. No more fiddling with spacers and wedding rings and torque wrenches.
These get mailed out to Woody tomorrow, for mounting as 17x2.5 rear and 19x2.5 front, sealed for tubeless.
Also made a decision to make an under-frame crossover pre-muffler, to then allow for a minimalist single can on the left side. The mandrel-bent tube I need to do that should be here this week and I can commence that experiment.