Ed Shilling at Hornshoppe Horns has been making ribbon speaker cables for many years. When I had his speakers, I noticed his ribbon cables on a photo he used on his site and asked about them. Although he didn't advertise them, he said he'd make them for anyone who asked.
They were copper flat ribbon speaker cables, by the way. They didn't look as nice as these Fidelium cables and the insulation looked like something Mapleshade made: kind of loose and baggy.
If I didn't have my present SCs, I'd give these a try.
All the best,
Nonoise