[Zeke]

My parents had one in the 50's. I think they bought it at a high end dept store much like Neiman Marcus is today. The hinge was simple and the little lid thingy fell off all the time and broke. It won't work w/o the little cap. The bottom vent was just a ceramic plug that you cocked in place to regulate the flow of combustion air.

All in all, a very trick device. Ours was red.