Where did you get the trim. Mine is shot too, and burgundy looks great.
I just went to Amazon to look up my order details (ordered in '14) and it seems that Amazon stopped carrying the moulding. All it shows is my order, but no info on the company, no substitute part number. A quick search of Amazon doesn't show anything close that might work either.
Called "Plastic T-moulding". It was made by a company in or near Eugene, Oregon, came on a 25' roll and was 1&1/4" wide. The width is what Fleetwood originally used. It's wide enough that there's a small overhang on the top that helps keep small items on the shelf as you drive. The 25' roll was just enough to do all the moulding in the RV with around 18" left over. Cost was $25.73 (including shipping), so around a dollar a foot.
Can't find info on that company so you'll have find a source on your own. If I do run into that info, I'll come back and post it here. They have (had?) a web site but I can't find that either, now. The big problem of finding it online is finding a company that will sell just 25' of the trim. Most have a minimum order of 250'!
Anyway, back to the shelf, here's a picture of the underside of the shelf. You can see the brackets are wood. At least on the shelf under the LR window. Some other shorter shelves are simple 'L' brackets. But, the reason is that with the other shelves, you're not in bed gazing up at them like you are with the J-couch shelf.
The screw is part of my modifications. I cut out sections of the moulding on the backside to make it easier to go around corners. Then I added a screw after a sharp bend. Probably unnecessary as the barbed part of the moulding really held fast.
