Large Round Tray (Over 12") - Unknown Mark - Origin

[gnemec]

I have a very large (Greater than 12") very heavy tray. It could be used for a cake for example. It has a slight depression in the center around 3" diameter and 3 welded on feet that raise it roughly an inch off the table. I've looked for sometime trying to identify it with no luck. It is not a plated surface, but a solid material as scratches indicate. Please any information would be helpful.

Thanks,
Jerry