The rims are the same pattern as WWII and post-war Jeeps... 5 x 5.5". with an approx. 4" hub (I think the correct measurement is 4.2"). So yes, M100 rims will fit the MBT/T3 series. In fact, the same rims were used on the post-war civilian T-3C trailer.
You can mount either the 6.00x16 or...
Well, if you want links, there are two useful ones right on this very website:
http://www.ih8mud.com/tech/pdf/trailer/m100-m115.pdf
http://www.ih8mud.com/tech/pdf/trailer/m416.pdf
Correction.
The M100 is also a post-WWII trailer. It was made in the early 1950's. I have one, dated 1953. While similar to WWII trailers, there are differences. It is also a "Cold War" trailer, plus Korean War. These have G-number (G747).
The WWII Jeep trailers are the MB-T (Willys) and...