Realized I needed to sand the roughness off the main axle threads. After that, the wheels slide on without too much coercion. Installed the axle nut and hand tightened.
Then worked on the right gear. Pressed the brake flange on, retorqued the brake flange assembly, an fit the main wheel. Did a trial fit of the brakes and the fairing bracket. Not a lot of clearance between that and the brake disc.
I'm going to wait to drill the axle for cotter pins until the weekend. Also need to get the wheel bearings cleaned and repacked.