Renee, if you haven't already, look at Ian G's Boler
buying guide in the documents section. It will give you a good idea of what to look at when you find a trailer for sale
. Most of what he talks about should apply to any of the older Scamps, Bolers and Trilliums in the 13 to 16 foot range. Not sure about 5th wheels or other brands.
When you do go to take a look, bring minimum of a good flashlight, builders square, something to lay on to get underneath the trailer, a small hammer and a small screwdriver.
Use the builders square to check for horizontal bends in the frame and the squareness of the entry door. I used the hammer to tap on the frame to make sure it wasn't severely rusted. The small screwdriver can be used to check for soft spots in the floor that may need repair. Regardless of how everything else looks, make sure the shell, trailer frame, and floor are in good shape. If you buy something 15 years or older you may have to replace the axle
if it is a Torflex style.