There should be a data plate on the trailer. It should provide you with the information regarding how much weight each axle can bear with certain tire size and inflation.

Also, write down the serial number and call the manufacturer and ask your questions to them specifically.

The manufacturer may not be able to answer the "insulation" issue - because they have no way of knowing if after they sold the trailer, it had living quarters added to it.

On your jack wall (under the gooseneck)... drill a TEENY TINY hole in that wall where you will NOT hit anything on the outside or drill from the outside in. You can fill the hole with any clear caulk. I'm sure you will be able to tell if that wall is insulated or not just by that. If that wall's not insulated (and I suspect not)... probably nothing else is.

The hinges you see is where you can move the saddle rack from the rear tack to the dressing room. I haven't measured it but I think it has a 8' long wall 4' short wall. I guess what mean about the walls is my trailers in the past looked like the ceiling of this trailer where there are beams showing, but in this trailer there is a sheet of metal over the beams so the walls are flat. Does that make sense? I will have to take more pictures. It definitely looks manufactured that way not an addition to the trailer by the original owners. I didn't know if maybe Sundowners insulated their walls... or if it was just a sheet of metal over the beams for appearance with no insulation.

As for the information sticker under the neck, there isn't one... I did try and contact the company and am waiting on them to reply.

Re: tires

If there is no data plate available, all you have to know is the wheel diameter and the width of your fenders. Any competent tire shop will be able to fit your trailer, with tires that are applicable. If you have done a search on tires within this forum, you will find several choices, which can be confusing.

The first thing is deciding what type of tire you want, and that can be directed by the wheel diameter. If you have 16" rims, many choices are available. 15" rims constrain your choices somewhat. Your first choice will be choosing between LT and ST tires. The first one is a truck tire that is commonly installed on trailers, the second is a trailer specific choice. The LT tires have some advantages, which are specified in the many previous postings you can access through the forums "SEARCH" function.

There are differences in the weight capacity of each. They are dictated by not only the tire sizing, but the number of construction differences that allow different carrying capacities. Generally, the more capacity the tires offer, the safer your trips will be with less chances of blow outs.

The better American brand tires cost more and are worth every cent. Under no circumstances should you consider a Chinese tire brand for any long term durability. Tire buying is not an area in which you want to pinch pennies. When you are hauling tonnes of weight at highway speeds, and the lives of your family and pets are involved, you want the best product you can find.

Find a good tire dealer; tell him or show him what you have, and he'll be able to advise you what size tires you need. Then ask for the highest weight rating in that size. You're much better to have too much capacity than not enough.

right now there are ST225/75R15 tires on it.  I just got worried when I saw they had a recall on the information plates, saying they had placed the wrong tire information on the plates.  Made me wonder if the previous owners knew what where the right tires to put on it.