Have now stripped, cleaned and re-assembled the rear brake and here's some useful information;
1. I had it back to front - apologies - the leading shoe is the one with the thicker lining and has lots of material on it (3.5mm minimum). It also has the auto-adjust mechanism.
2. The trailing shoe once cleaned actually has more material left on it than I thought and no doubt started much thinner than the leading shoe. It's got a minimum of 2mm left.
3. The shoes are made by Caparo and they appear in their classic car catalogue; an abridged version is
here on Dropbox. .The shoes are Caparo part number HF206. Don't know if they are available from factors, haven't asked.
4. I took a series of photos of the mechanism as I took it apart, There is a pdf of photos with minimal captions
here on Dropbox. Might be of use to people.
5. The adjuster mechanism is easily re-set to retract the shoes as far as possible for refitting into the drum; it then ratchets out when the brake pedal is pressed.
