72 Distributor interchange

[John Middlesworth <jape@email.unc.edu>]

My 72 MGB distributor needs a new vacuum advance and a set of springs for
the weights.  The springs appear to be unavailable and the vacuum
advance ridiculously expensive.  Should I buy a new distributor ($159) or
look for a good used one?  Or should I just try to fit a vacuum advance
and springs from another year?  What's interchangeable?  Would there be
some advantage to going with a distributor from a different year?

John Middlesworth