Managed to remove the brake caliper and hub assembly and now need to order some new bearings.
I seem to recall Nicholas (previous owner) saying that he had the front brake pads relined as the calipers were a bit of an unknown quantity apart from being made by Girling however he was under the impression that BG Developments of Bromsgrove did supply them originally according to Rory at Marcos Heritage who had some dealings with the car at the time back in 1985 when it was born.
As these calipers like most other bits on the car have stood still for probably 3 years now thought I would give BG Developments a call to make some enquiries, have just spoken to a most helpful Caroline who having been given the dimensions immediately identified them as a Girling AR5 and they do offer a recon service and can also supply the brake disc rotor either off the shelf or made up to suit this special AR5 caliper. Having looked on the www these AR5 calipers are certainly not cheap to buy new at £375+vat plus the cost of pads.
Hopefully I can get down to Bromsgrove over the next couple of weeks as it's quite local to me and see if they can be rebuilt,
If you are wondering what the holes are in the chassis rails, I have carefully drilled several all over the chassis and have bought some rubber grommets and once it is on wheels I can roll it out of the garage and fill the tubes with waxoil then seal the holes and hopefully repeat this exercise every few years,