I'm not sure. It's for a long-time customer in the 15-20 year range who is an architect. He only had a minute when he stopped in and I said I'd look in to it by Monday afternoon. He wants something like a Nielsen 15 profile with the bottom part, the channel where you slide in the hardware, eliminated. So, that cuts down on the complexity I think. Don't know what the heck he wants it for yet. He designes churches, could be anything. I found some brass fabricators on Google but was wondering if anyone knew of anyone that has been good or at least has worked with a picture framer.
I checked with SmallCorp and they discontined making brass frames due to difficulty with the stock bending during fabrication. They had a profile much like you describe. They know of no one that is currently making custom brass frames.
You might check with A Street Frames in Cambridge, Ma. They do custom metal frames.
You might look in your local area for "BRAZING" fabrications. Brazing is the process like welding for joining these materials but at much lower tempatures. Ask them about a rounded J Channel stock (they typically refer to J channel as being square cornered with one leg longer than the other). Should you be unable to find one locally check the internet for brazing allows and services. Ask these suppliers who they would recommend.