Well guys we did it. Spent yesterday removing the axles, fenders, and tongue and today we mounted it on the trailer. I welded nine 1/2" thick 4" x5" spacers on the bottom of the enclosed trailer frame spaced around the perimeter and then welded it down on the gooseneck.
I am going to build some fold up stairs to get into the door on the front part of the trailer and getting in the back for the tools is actually easier now. You have to walk up the ramps on the gooseneck but once you are there the enclosed trailer is lower than before since it has no wheels.
The UTV is 10' long and really no way to put it sideways or anything like that. With a few inches space from the back door of the enclosed the rear of the UTV bed is about 10" past the rear of the trailer. I think the legal overhang limit is 3 or 4' so all good there and the tires are completely on the trailer.
All in all I am pleased with how it turned out. A little more grinding and some pain and it will be done.