Burros and Uhauls have a 'double wall' construction, using an inner and outer shell (so you wind up with a smooth inside wall kind of like a shower stall with preformed seats, etc). Uhauls are not insulated between the shells, there is just an air gap. Some Burros do have insulation, but not all, because it would have been an option to the purchasers. Burros produced a 'wide body' trailer which is slightly larger than standard 13 footers which gives you a bigger bed. Both Burros and Uhauls are no longer manufactured but you can get them used, many times in very good condition.
type trailers utilize a single shell construction which is lined inside with either a smooth or fuzzy material (depending on the make/model year). That material is has a thin insulative material beneath it. Since they're a single layer of fiberglass, anything attached to the walls such as the kitchen area cabinets or closet, is attached through the shell with rivets/bolts, which is why they have the round caps on the ouside of the trailer (these cover the bolt heads). Uhauls/Burros do not have the bold covers because their inside shell is fiberglassed to the ouside shell in certain spots along the top and bottom, so there are no bolt holes needed. Uhauls/Burros sections are attached in the middle with a raised seam which runs vertically from front to back. Scamp type trailers are attached horizontally around the middle with what is called 'belly bands'.
Go to the 'Albums' tab at the top of this page, and you can go through photos of all the various trailer brands so you can really see what they look like inside and outside.
Also, check out the For Sale
section of this site for many nice trailers. There was a VERY SWEEEEET one for sale
(Contempo condo) right in California by one of our members, Joe Balla. It may still be for sale
? Welcome to the group and Good Luck on your search !