Throttle return springs

[Edward Hamilton <hamilton@ptd.net>]

I shall be installing the 1-1/2" SU's on my 1500 spit this week end.  In
getting my stuff together, I find that I am missing the throttle return
springs.  All of my reference materials (catalogs) deal with spitfires
and, as such, don't speak to HS4's -- since they didn't appear on North
American cars.
Would someone please provide me with the part number and supplier of
said springs.  Should a pair be resting in someone's' garage -- they
will, naturally, be most appreciated.

Regards,
Ed Hamilton