eBay UK is always a good bet for things like this. http://www.ebay.co.uk

There may not be anything there now, but keep checking and you're bound to
find something useful.

David

Hi Dave,
   To be honest you may be in for a long wait. Herald rear overriders
rarely survive in good condition, those that do are usually on very tidy
cars which aren't going to get broken for spares. The rot usually starts
behind the lower captive nut and even if it doesn't penetrate, the overrider
often has to be cut away from the car when the captive nut is seized. The
trick to avoid this upon reassembly is to use a length of studding in place
of the bolt, then slip a nut on the end inside the boot.
There are 3 different manufactiurers of reproduction rear overriders, one of
these produces them using the original tooling so at least they will fit.
Quality of chrome is likely to be an issue with any new overrider,
   Cheers,
       Bill.

--
Rarebits4classics
      .......just what you've been looking for

PO Box 1232
Calne
Wiltshire
SN11 8WA
United Kingdom
http://www.rarebits4classics.co.uk

My Vitesse came with two identical rear over-riders rather than a
properly handed pair, so I had to buy a pattern replacement for one
side. I've a nasty feeling that my surplus one is a N/S, but can't be
sure until I've checked...