Originally Posted by Goondog
Mine are cracking too and don't really fit the shell very well anymore. I'm thinking of cutting some aluminum the same size and Olympic riveting it on. Then cutting some holes for standard round trailer lights.
Your idea may work out just fine and it may actually be the only way to go because I don't think new lenses or the metal light boxes for the old Monarch lights are even available any longer.
In my case I'd already paid about at least 250.00 for the Sealed LED light kit for old 4.25 Monarch
to replace my old lights and replacement lenses and new metal boxes, etc. So, in my case I already had a pretty big incentive to make my situation work.
I ended up using a combination of clear JB Weld and two part resin along with some fiberglass joint tape to reinforce them from the backside. Mine did not fit well either. The former PO had caulked the crap out of them. I used a couple of different widths and thicknesses (3/8" x 1" and 1" x 1") of adhesive backed closed cell weather strip foam (like might be used for boat hatches) to seal behind them around the perimeter, top and sides. Anyway, this seems to have worked pretty well.
Quite a pain in the A** to save some cheap plastic.
If I get some time I'll post some pictures.