Not sure who you are asking.
I’m not sure what I will do with the hubs/wheels. My plan is to use rear wheels on the front and somehow add bearings. It will probably be welded in hubs, not bolted on. I don’t have any wheels I would use for that so modifying the centers of the rear wheels to accept bearings is my thought.
I bought a hole saw to cut out the centers of the rear wheels for welding in those bearing sleeves shown above.
That should make a slip fit hole for the sleeves. I need to make an ‘axle’ with the flats ground on it, and a center hole for a guide so I guarantee the hole saw cuts accurately in the center of the wheel.
The axle looks like this now, so grinding flats on a 3/4” shaft will work I think.
Drilling a center hole should insure concentricity. I would cut off a FNR axle, but I don’t have any total junkers.