So, we are into the annual inspection on our J3 and removed the tailwheel assy and leaf springs, rebuilt the Maule SFSO tailwheel assy(we are not sure that it is the SFSO model as it has no markings we can find, but it matches the parts breakdown) and ordered a new solid rubber tire from A/C Spruce using their Maule parts breakdown and part number. The tire arrived with all bearings installed and would not fit our axle. Our axle is 5/8" diameter and the t/w bearings are 1/2" ID. I called A/C spruce and they said that is the tire I need. I called Univair and they measured the ID of their Maule solid rubber tire bearings and said 1/2". We are wondering if 1/2" is the standard axle size for the Maule SFSO and if so if someone in the past has swapped the original 1/2" axle for our 3/4" axle. The tire that was on it was not original Maule, it is marked "K & M 6 x 2.25". We are now at a standstill. I researched on line and called some tire suppliers and could not find a tire with bearings installed with a 3/4" ID. I could also not find any information on K & M 6 x 2.25 tires. As we see it, our options are change our axle or buy a tire less bearings and find bearings to install which match our axle. Any suggestions?