another brass (-ish) thing, is it a percussion instrument, or part of a lamp, or ???

This one's been puzzling me for several months now, I remembered to dig it out when the cymbals came along recently. This thing was another trash-pile find at a house at least one percussionist had moved out of, and came somewhat painted flat black as seen, with the addition of a 'homebrew' mounting method to an 'L' shaped piece of chrome tubing using the small hole at its narrow end. It seemed as though somebody tried to set it up for use on a stand like a cymbal or gong, perhaps with it fixed in a horizontal position with its open part pointed to the side but more likely hanging vertically like a bell.

Its metal *looks* like it could be spun brass (again, like a cymbal) but closer examination reveals spots on its outside where surface rust has erupted through what is only brass plating -- it is steel inside, and definitely attracts a magnet. Taking a gentle wire brush to it scraped off some of the icky flat black paint still showing as brass underneath, but the rusty spots remain gray iron if the rust is scrubbed off. (pic 3 inside, pic 4 outside) It is 13-1/2" across the open end, and a little over 9-1/2" deep. If there are any markings on it they are very well hidden, I examined it closely for any signs of stamping or even a previous painted logo or label -- there are none discernable.

BUT, if it wasn't intended to be beat on like a gong, What the Freakola WAS it?? Part of a lamp or light fixture maybe?? A cover for something?? I don't really have any other guesses for anything I can think of, WHAT SAY YE?? I know all y'all here at CW have creative minds that notice details in stuff -- does it look like anything any of you have ever seen before?? <beg> ;-) :-)

Marking this as 'tools and hardware' for now, also 'unsolved mystery'...