don't know if this helps but my cj2a rims do fit on my 1/4 ton trailer since the jeep rims have the larger center, though you do have to use the jeep acorn lug nuts to properly align the rims
with the different offset of the m151 wheels, if they were placed on an m38, the distance between the wheels would be less, to the point that if trying to turn the vehicle, the tires would likely rub the frame. i saw one like this on ebay some time ago, and it looked spooky!!