Not nearly enough information, but with a wood interior. the 5500 generally can be a lot more work than the 1300. The fiberglass interior cabinets on a 1300 are nearly indestructible.
The exterior fiberglass should not be brittle. Use what you learned on the 1300 and apply those lessons to your inspection of the 5500.
Having restored a 1300, I feel like I kind of cheated when I go to vintage trailer shows, as everyone else has done SO MUCH MORE work.
With a 5500, you are talking a trailer close to 40 years old. Inspect carefully, do not assume everything is OK. And do not trust owner's comments. Not to say all sellers lie. Some just don't know. I've shown several sellers defects they overlooked and never mentioned.
The number 1 item needed for any older trailer ownership is TIME. People without a ton of spare time may be better served buying something a lot newer.
Go to the upper right of your screen, click on Manufacturers, then choose Trillium
. Read all the 5500 project threads you can find, along with other Trillium discussions. With this knowledge, you can be an expert inspector. Then decide what you have the time for.
Trilliums are hard to find, 5500s even more so. But unless there are obvious signs of recent restoration work: belly band and windows
for example, assume that work falls to YOU or whoever the new owner ends up being.