Have you looked into the possibility that a spring from, say, a lowly Simplex Prestige derailer might be the very same part?
Short of any expendable Simplexes laying around, could you post a picture, and maybe some critical dimensions of said spring?
David Snyder
Auburn, CA usa
>A long short, probably, but does anyone here have or know where to find
> an upper pivot spring for a Simplex SX-660 "Super LJ" rear derailleur?
>
> TIA...