HAHAHAHHAHA, I have found the hub info.
http://www.randpcarriages.com/tech/axlechart.html
The spindles are a #42, which is used for both the 5200 axles and the 7000 axles. Only difference other than the lugs are the outer bearings, which simply correspond to the rating on the axle.
So the hubs I posted are an easy swap to get you to six lug axles on the M1101/1102 trailers. Looks like I need some extra cash soon to order mine and a set of rims. (New rims for the suburban and put the old rims on the trailer)