Your bike - if she is a CB bike at all - was manufactured after CB went into receivership in 1956 and the brand was later taken over by Holdsworth. The bad news of it (apart from not being a genuine CB) is that Holdsworth gave up on coding the date of manufacturing into the serial number, so there is no point in holding onto that.
Guessing by the frame lugs (Nervex Pro) it could be a CB Cordon Bleu frame from anywhere in the sixties, however the fork crown design suggest a different era (mid-to-late seventies). So, either the forks are not original to the frame or the whole frameset is of a different brand.
