Welcome to the SOC.
Your Trailer has been repainted. I like the color combination and design.
If you were to post pictures of the light next to the door it would be helpful. Also some pictures of the interior. If interior has some original fabrics, it is a clue. Even the wall paper colors and patterns can help.
Sunline Fan can give more info if you respond to the "list your vin #" thread.
I have a 1983 T-1550. I think (based on your light, though hard to see) I think you are about 1985.
TT:1983 Sunline T-1550
TT:1996 Sunline T-2053
TV:2005 Toyota Tundra Double Cab 2UZ-FE i-Force 4.7 L DOHC (MFI) V8 4WD SR5 Automatic
P3 break control
"I know a lot about nothing and nothing about a lot"