Ever since RENA took over distribution for North America, they threw all enthusiasts of older models under the bus. (And then they somehow expect us to buy their new bikes?)
You can try RE of Ft Worth, who bought out remaining parts from the previous US distributor.
If they don't have it, then you are left with Hitchcocks in the UK, or India vendors on EBay. Hitchcocks is more expensive, but they are better.