The capri axle I have is missing its internals and drums although the backplates are mint.
I know these cars don't need a lot of rear brake effort but do think it's nicer to look at discs through the wheels.
I wondered if the rover 620 brake callipers could be made to fit with appropriate brackets. If so what discs should i use?
Has anyone else done this or got photo's or web links?
Would I need a bias pedal box to go this route or will a proportioning valve still do the job?

Cheap Fiesta front disks will go over the studs but you'll need longer studs then. If you can get brackets made you should in theory be able to make any rear caliper fit.

MK3 Escort non vented discs -- BG2376
see https://sslrelay.com/buypartsby.co.uk/discs_details.php?recordID=2404

The Rover caliper brackets look like they will be tight to come off but there is just enough room to get a slim spanner in and the bolts are usually quite free.. I have have a set of 623 calipers lying that I prob won't now use -- one of the calipers needs a rebuild.

Practical Performance Car carried out a rear disc conversion a while ago on Will Holmans V8 Capri , may be of help to you if you can get a copy. BT your showing your age with your avator . Blakes Seven?