Looks like a lot of Mulberry Metals items. They are in Union, NJ, as I previously posted for a 4 gang FS cover for someone. I used to see a lot of wierd combo plates that were special orders; tog/recept/tog; duplex/single/toggle/single; block/duplex/tog/single/block, etc.
Mulberry would 'special' anything you could possibly come up with. Materials from base tin, to solid (real) brass; stainless, all grades, mag & non-mag; plastic; wood; lexan
and a ton of 'decorator' finishes.