Collectors of early variants of the M16 rifle can check enquire at Bang Bang Big Boys Store in Hong Kong aboout the DNA XM16A1 (603Early) GBBR that they have in stock. Only HK-residents can order from their store... "XM16E1 is the first M16 series to be put into the VN war. It is the first "03" type M16 of the US military. 03 refers to the "increase aid" so this is only an early 603 MOD.