TR6 Vacuum Retard

[Martin Libhart <mlibhart@feist.com>]

Is anyone aware of an inexpensive source (i.e. less expensive than the
'big three') for the vacuum retard unit for a 74 TR6 distributor?  Most
of our usual sources are anywhere from $35-$40; surely the diaghram unit
is available somewhere for much less than that. Anyone with recent
purchase information?

Martin Libhart
1972 TR6 (driver)
1970 Spitfire Mk.3 (under the knife)