Hi Steve..That will be the early (expensive) 'combination' levers with a seperate Adv/Rtd lever on the bars...These routinely fetch £300 plus a pair, without the adv/rtd lever.
Cornucopia replicate some parts but not the whole thing I don't think.I don't know of any other replicas....They turn up fairly frequently on e bay but expect to pay the figure quoted...Ian
Before deciding that the early levers (shared with exotic pre-war models) are a must, it probably isn't a bad idea to think about what is to be portrayed when the bike is fully restored.
If the complete machine is from 1940 with large fuel tank, valanced rear guard, oil tell-tale and all the nice bits, it would indeed be a shame not to fit original levers but if it has a replacement, probably later, engine and shows evidence of going through the rebuild system then there is a good chance that later levers would have been fitted during wartime service.
Although serviceable parts were re-used, one of the reasons that these early 'consumables' are so scarce and expensive is that later parts were frequently substituted.
You may well find bits and pieces to build up a set of levers more cheaply at Stafford but it is likely to take more than one jumble. If you're going down that route then arm yourself with photos and dimensioned drawings or you'll end up with an even bigger box of 'almost right' parts than I did !
Cornucopia do keep some genuine parts for those early type aswell as i just bought a genuine 27-7827 clutch control body from him.
Someone at Stamford hall was selling repro lever arns, they were spot on aswell & had the parking brake ratchet serrations present on the brake lever.