Some one must be making square section springs because I bought 4 of them last year fromBill Green when he was selling down his stock prior to the proposed sale of the business which fell through.
I would guess they originated in India where he got a lot of parts made but these seemed to be good as I am using one right now & have another in the model S .
The M20 one has done quite a few thousand miles on his spring without any problems .
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.