Yes, dealers aren't the snappiest people to recognize models of used trailers. Sad, but true. Most don't even make an attempt and just use a length or make up a name/number.
For your window, is it the gear that's stripped or the knob? I have heard the window gear boxes go bad, but more commonly it's the plastic knob that strips. They are readily available at a dealer in three colors: black, brown, and white.
To help you with your VIN, it should be 1LC2S1K2_KD22_ _ _ _ The spot between the 2 and K is numeric or X. The last four are all numeric.
2007 T-286SR Cherry/Granola, #6236, original owner, current mileage: 9473.8 (as of 6/18/21)
1997 T-2653 Blue Denim, #5471
1979 12 1/2' MC, Beige & Avocado, #4639
Past Sunlines: '97 T-2653 #5089, '94 T-2251, '86 T-1550, '94 T-2363, '98 T-270SR