David, so glad you are back!
To the question on how-to for Trilliums, go to the upper right of the page, click on Manufacturers and select Trillium
There you will find hundreds of threads on repairs others have done, including David. I found David and Randy Bishop postings key to my learning. There are others as well, but those two have both owned many Trilliums and done thorough repairs.
is a great trailer!!! But, it has some well documented shortcomings. Windows
, belly band, body to frame bolts, door hinge mounting, frame issues. But realize your trailer has already lasted over 45 years, which is a testament to the good design.
If you use the search function, be sure to search via Google.