Do some research on "snap on Duals." Around here and I am sure elsewhere, the receiver wheels have a "bracket" on them....then the other wheel simply snaps onto the wheel.
Ive done it a few times on a small tractor and also a pickup i used off road.
I cut the center out of one rim, and then welded some small pieces of steel on the outside of the rim(where the weights go). then welded both wheels together side buy side. Even made wide chains for them as well.Worked great.
05' JD 790 - 53' Ford NAA - 70' Massey Fergusen 135 diesel - 67' John Deere 3020 deisel - 77' John Deere 2130 - 1950 John Deere MC
The old combine on the farm has a set of tires and wheels bolted directly to the inner tire and wheel with treaded rods through both rims. They are slightly smaller diameter so the inside wheels take most of the pressure. They do not really help with traction much but they do help with flotation. It has been working like that for as many years as I can remember (15 or so, maybe longer it is a mid 80's combine)