🔎 UNIDENTIFIED Odd brass piece

[cudamark]

Any ideas on this two piece brass "window frame"? Has brass rivets holding both halves about 1/2" to 3/4" apart if they were spread. Rivets in each corner, but, only rivets half way between them on two sides. Found in an area with all sorts of targets from the last 100 years, so, no hint as to age other than how it's built. Age and use would be what I'd like to figure out. Pilot light window maybe?

 

[creskol]

Any ideas on this two piece brass "window frame"? Has brass rivets holding both halves about 1/2" to 3/4" apart if they were spread. Rivets in each corner, but, only rivets half way between them on two sides. Found in an area with all sorts of targets from the last 100 years, so, no hint as to age other than how it's built. Age and use would be what I'd like to figure out. Pilot light window maybe?
View attachment 2205831View attachment 2205832

I am not 100% sure, but I am relatively certain that your frame held a piece of mica and was a sight glass from some sort of combustion appliance, but more commonly seen in old kerosene, oil, and coal furnaces and heaters. It was to view the flame and not a pilot light.