I'm a small one-person manufacturer of Eurorack modules based in Belgium.
My modules are available fully build, as kit or as bare PCB's.
All my modules are designed with through hole components and have publicly available schematics. This ensures they will be repairable for decades to come by anyone with a working knowledge about electronics.
Metal-O-Tron II, Can I kick it?, VCF-3, FUZZ-1 and VCF-1 are among Skull & Circuits most popular products.