Rolax was manufactured by Jones and Sons manufacturing jewellers in High St, Christchurch.
Early advertising shows that Rolax radios (possibly a play on Rolex, a brand that Jones and Sons sold) were manufactured on site by an 'expert radio engineer' (their words). In 1939 advertising shows that Rolax manufacturing had moved to 175 Manchester St.
It appears that Jones and Sons may not have survived the wartime and the brand appears to have lapsed for some years until rebranded Bell Colt sets started appearing again with the Rolax brand, and most are seen with a Sedley Wells transfer on the front. It is unclear if this was a reboot of the brand by someone formerly involved with Rolax or just an opportunity to use a known brand name. What is known is that it appears to have been short lived, with Rolax Colts being sighted with 1953 date codes only, and the author is unaware of any other Rolax models existing after that.