Done:
https://www.imcdb.org/vehicles.php?make=Rex for the Chinese recent models
https://www.imcdb.org/vehicles.php?make=AB-Rex for the Swedish mopeds
https://www.imcdb.org/vehicles.php?make=Rex-Motoren-Werke for the old German mopeds
https://www.imcdb.org/vehicles.php?make=Rexworks for the American heavy equipment