"Casa Montagnac" was a very well renowned shop in Esmeralda st, downtown Buenos Aires (Argentina). They used to have lots of things for hairdressers (from hand tools to electric ones) and a nice sharpening workshop. They ended up closing down a few years ago.
They might have sold some things with their own brand, but they probably made just stropping/polishing compond bars (I still have one around there).
Rgds.