This thread sure has covered a wide range -- trailers, lawn tractors, fairly good sized farm tractors, firewood, ... I will throw these in for good measure:
1) With the 4wd lawn machine and a 60" deck I say get a 6 1/2 x 12 ft trailer. The 6 1/2 is important because my Kubota
BX2200 (and your Massey) will not fit a 6ft wide trailer without squeezing or even loosening something. The 6 1/2 x 12 is not only ideal, it is no more expensive than the narrower one. Plenty of good used ones around too.
2) When hauling any equipment on a trailer make sure you have "plenty of tongue weight." With larger machines (e.g. farm tractors) my rule of thumb is run the load forward until the truck hitchball is lowered by about 5 inches. Having plenty of tongue weight is the MAIN way you have to preclude fishtailing. The principle is still the same with small trailers and loads but of course smaller scale and less truck deflection.
3) The 6 1/2 x 12 single axle trailer is great for hauling firewood over small distances. Just experiment to see what you can handle in your circumstance. I can haul a cord or two around the property but watch what you are doing since most of these little tractors have worthless brakes and you are vulnerable on slopes, obstacles, etc.
4) By the way, a gadget that is GREAT for maneuvering trailers around (even fairly large ones, using the little tractor, when trailer is not attached to the truck) is a "T" that mounts on your 3pt hitch and hosts a receiver hitch. Photo below.
