Hi Trevor could they be new old stock as Bill sold me complete float bodies a while ago that were left behind in India by the British. He had some good bits prior to getting parts made in India. He offered me carburetter parts last year but as soon as I saw the finish on them I knew they were Indian made and inferior quality.
Whilst sourcing other springs I thought I would look at the clutch spring and the crank shock absorber too as John has given up. At a push they could use the same wire.
To start with they are not made from rectangular wire, so new tooling will have to be made for the wire. If it was rectangular, the metre long piece of wire would be about £30.00ukp for carbon steel wire. I didn't ask about silicon chrome steel wire, but that would give a better life.
So once you have the wire in the correct profile, it seems the spring winder also needs bespoke tooling.
I haven't given up the research, but it's that same old thing again. How much would someone pay for a spring?
50 metres of rectangular wire is about £1500.00ukp, so not unreasonable.
Test figures (specs.)for the springs are available and round wire would do the job as long as the poundage was correct...I guess it's down to asking a spring maker whether the poundage and essential dimensions provided are possible with a round wire...
Later BSAs did use round wire for the engine shock absorber when the change was made from 4 lobe to 2 lobe cams but the poundage was completely different as the gentler radii of the 2 lobe type cam required a heavier spring for correct operation...Ian