I'm puzzled by the speedo. The application of paint to a dull-chromed "ridged" bezel doesn't conform with pre-war practice. The screws from the type plate have clearly been removed at least once. What might the small "SR/42" indicate ? "Service Repair" perhaps ?
Presumably if an instrument went back to Smiths for overhaul, for guarantee purposes, it would be fitted with a data plate bearing the current date ?
We'll never know, but could this instrument have been a service-repair for a pre-war RAF Norton sidecar outfit or similar ? It's quite likely that those in use for tasks such as ferrying messages and staff around the Air Ministry might not have been re-painted.
RAF blue Lucas or Smiths instruments are bizarre, but I'll ask another question: 99% of the "projects" that have been bought by forum members still have some original paint somewhere (under a coat of post war civilian paint, or inside the brake drums, or inside the primary chain cover, or inside the headlight, ...). I'm keeping a Register for the WD Royal Enfields, and I have to say that I have never come across original RAF blue paint on RAF contract bikes (and there are a few...). Has anybody ever seen original RAF blue on an unrestored bike...? (BSA, Norton, Ariel, ...)
Lex the only WD bikes with an Anti Clock speedo were the Royal Enfield WD/G and WD/L. Both mine came without a working speedo. I acquired a NOS 1942 dated AC speedo with the correct part number on the brass tag which is on my WD/G. For the WD/L, David Woods reworked a standard pin drive speedo for me to reverse the action. Ron