If anyone comes across this thread, these rims ended up working.
It does not say so, but they are dual pattern , 3x2.5in with 1/4 holes, and 3x58mm with 8mm holes.
https://www.bmikarts.com/6-VanK-Non-Machined-Classic-Kart-Quarter-Midget-Wheel--Black-Powder-Painted_p_38333.html