Hmmm...I too have gone that route. I bought a Boler
in Winnipeg in summer of 2013 and blindly towed it to Calgary only to find out that ignorance was bliss or I never would have towed it "as is!" So far, I have completely gutted the trailer to find that the whole back end, up to the belly band had been in an accident and was pretty much all bondo with the pieces of fiberglass very poorly reglassed together. Every single wooden floor was rotted out and there were up to 1.5" gaps to air where the broken shell didn't meet the floor again! All the fiberglass cabinets had cracked in the accident (or whatever had happened to it) and were hanging loosly but not adhered to the shell!
My approach was to simply gut to the shell, including the insulation. After trying EVERYTHING to get the insulation off, I started scoring it in strips with an exacto knife and then I put a scraping blade onto my dremmel tool and it actually came off pretty easy that way - it only took about 25 hours to remove the insulation (that was the easy way!!).
To get the shell off the actual trailer, the screws and bolts were so rusty, i ended up having to cut the wooden floor around the bolts and just bust off the screws as I found them. I ruined some pretty nice tools doing it!
I then removed all the windows
and hung the shell from rafters in my garage. I have replaced the back end floor so far - that too was hanous!! In removing all of the old rotted floors, there were some pieces of the fibreglass that had held it in that I left in place in order to have "little shelves" of fiberglass to hold up the new floor. I cut out most of the fiberglass if it didn't already break off with the removal of the old floor. I used 3/4" plywood and cut it as if it my shell was in perfect shape. I then had to sand down the edge of the floor to bevel it with the bevel facing down, as the shape of the trailer that shape. I used chopstrand fiberglass and put one layer on the plywood (ended up on both sides, rather than just the bottom side as I put it on the wrong side initially! I guess it is just added weight! I then lay the floor in and as I said, had it somwhat supported by some of the original strips of fiberglass that had secured the original floor - it was put in by a 4 or 5 inch strip on both sides of the fibreglass, essentially sandwiching the floor to the shell. Because my shell had been pretty poorly repaired to begin with, I had some pretty big gaps in spots where the shell didn't meet the floor anymore. I screwed through the shell to the floor to bring the shell as close to the floor as I could. I used 6" strips of cloth and managed to glass both sides of the floor - that was not easy to work on the bottom side as the fiberglass was difficult to work with - I had the best luck working in short strips and only mixing up small amounts of resin. I have NEVER worked with fiberglass before so it is a learning opportunity! Whew! I have a long way to go with this Boler
Baby! I will figure out a way to add some pics!!