What I can tell you is that "corneta" means hornet in Portuguese, and is the brand under which they were sold in Brazil (maybe also in Portugal). Corneta razors are by far the most common on flea markets and antique shops here in Brazil, followed by Heljes, Filarmonicas, an occasional Puma and swedish-looking but poor-finished "Cruzeiros" made on swedish steel (Aço Sueco) - maybe popular-priced Swedish items. British and USA makers are "white flies".