Here is what mine looks like. Found it on eBay years ago. I have no idea about its origin. The glass was broken when I bought it. A little super glue keeps it in one piece. The strap that holds the glass in place is brass. It is mounted on the top of my stake bed, behind the cab's rear window.
'57 GMC 102, Original 347 V8, HydraMatic, 3.08 rear gear, added A/C, disk front brakes, HEI, AFB carb, '98 Honda Black Currant paint. T-boned and totaled 10/12 '52 GMC 152 Stake Bed, Original 228, SM420, added A/C, HEI, disk front brakes, '67 Chev 3.55 rear gear. Gets used as a real truck.