Is there a machinist in the house

Remove the clips and screws and discard them. Remove the glass and clean thoroughly. Clean the frame and wire brush if needed to remove corrosion and grime. Apply silicone sealant to the frame, press the glass in place and masking tape it securely until the silicone sets up. Remove masking tape and clean away excess silicone with razor blade or whatever. Repair should now be good for another forty years or so. HTH

Joe

See if you can find the metal screw clips that were used on metal screen/storm doors. They had knurled screws which are sufficient for keeping tension on the glass. The newer ones are plastic and don't have screws. Try a good hardware or a storm door installer. You could "antique" the clips with hobby paint from a hobby shop or craft department. If the fixture is in poor shape, consider replacement. They make some attractive gas fixtures. Your gas company may offer some. Just call them to find out.

I'm not sure exactly how these clips are shaped, but banding iron or strapping is handy for fabrication jobs like these. I'm talking about the type of steel banding used for shipping on pallets and heavy crates. You can usually find some for free at a dumpster behind any industrial or large commercial business. Assuming you have a drill and some basic hand tools.

I found these at Home Depot before I got your helpful message, but that is exactly what I brought home to try. It has been raining all day today. I will give it a shot tomorrow.

The bracket will be offset backwards to holding a mirror, but I think it just might work.

Thanks