There appear to be at least 4 different types of landing wheels used on 1 ton trailers. I do not know if there is significance on what type was used by what manufacturer (need input on this). Here are the versions.

Wheel 1: This wheel is on my steel trailer. It is a welded wheel originally consisting of 3 pieces. Left side, right side, and center hub. There is a Zerk fitting on the hub. The two identical halves are joined and then welded together on the flat ground surface and at the center hub. It also appears that the  mounting fork is different than the other wheels

Wheel 2: This is on my Wood trailer. This is either 3 piece wheel or 4 piece wheel. This wheel is not welded together but is bolted together by 8 rivets through the center hub. The outer striking surface is also a separate piece. ( I am unable to tell if that is part of the center hub or if it is a 4th piece that is welded to the  two outer wheel "rims) This wheel has distinctive sides two it while the wheel on #1 just appears to be rolled over.

Wheel 3: Is a typical type of wagon wheel. 8 spokes on what appears to be a cast band.

Wheel 4: (Need additional picture) is a pneumatic tire mounted on a traditional trailer rim. Picture 4-1 is off a water buffalo. These tires may have been used more on the WB than others.