Spring, centre stand, Norton brazed frame swing arm

Centre stand spring for Norton single down tube brazed frames with swing arm, 1953 to 1957? Should also fit other models except featherbed, Outside diam 3/4in, swivelling eye on each end, eyes are 6-3/4in between centres fully extended, 3/8in internal eye diam, eyes restrained approx 5-5/8 inch centres
Original Part Number:
16937; H12/527 - Prop stand return spring