More than 40 years ago, when I was stuffing around with my first 'bike, a 1947 MSS Velo. I read somewhere that the "CV" part of the Miller nomenclature stood for "Controlled Voltage". The inference being that it referred to the whole shooting match, not just the headlight. Miller supplied other stuff complete with wiring so I reckon they would have supplied the loom; but just a guess on my part! Found a new pair of K.L.G. FE70 "Corundite" plugs in my shed yesterday, are these right for early "B" Rapides? The wiring harness in the Parts List also has a Miller part no. All "PR" part numbers are bought in components, the "PR" stands for "Proprietary" if my memory serves me well. I don't think the Vincent factory had an area for loom manufacture, either. Also look at Parts description for PR18/1AS- Headlamp complete with etc.