Scheirich Kitchen Drawer guide

My Scheirich system is circa 1980 and uses triangular metallic glide assemblies with nylon rollers at the cabinet entry point. These rollers fit into the side glider channels on the drawers. I need to replace one of these triangular glides because the nylon roller is broken (it is riveted into the metal bracket).

Anyone know where to access these triangular glides -- they seem to be unique to Scheirich. Does anyone make them or retail them?