I am not a scale guy, but Windys video, on You Tube, showed how he did it with balsa wheel pants.
Video number 304, 5, 6 or 307. I watched it the other day not sure which one it was, a friend of his building a Cardinal.
He split the pants in half, laid in 1/16"(?) ply on one edge left an area extra at each end for a blind nut. Inlaid ply on the other half of the wheel pant to take the bolt. I wasn't paying that much attention, I had it on in the background, but that was the jist.
Craig