Those are Dubro axles. The wheels are put on and the axles are measured and cut. The end of the axle is heated to orange, cooled, and a small flat is ground on one side. Then a hole is drilled (maybe #60) at the ground point thru the axle to accept a short piece of .032 aviation safety wire. A washer or washers are used for spacing. You will not lose a wheel in a contest using this technique!
I fly on turf, so there will be no pants and the associated hassle.
Wheels are Dubro Lite 2-3/4".
I cannot guarantee the function of the stiffeners as the plane has not flown yet, so you're on your own. They were designed with scraps of information I gathered word-of-mouth. Kyuho Lee checked the photos and felt it functionally matched the structure he added on his Agenda, but I deviated from what he actually did by adding the front stiffener instead of carbon tow around the front screws.
What? No comments about the tailwheel?
-Ron