Sorting through my spares today I came across a rear stand spring I don't recognise in amongst the others...
Visually it looks at first sight like an M20 spring, coiled with the 'loose wire' ends held in place by the reduced diameter spring winding on each end of the main spring...
However, the 'eye' on one end is considerably longer when pulled to its full extension...
So, if you imagine an M20 spring but with an extended 'eye' on one end...
Total length between the 'eye' centres on full extension is approx. 7 1/4"...
I suspect this is for an earlier BSA model as it conforms generally to the BSA pattern...It is a NOS item....