The Demon Tweaks catalogue lists the GKN Motorsport joints, maybe they could supply the standard Capri CVs?  If the standard CV is no longer available (even the same unit from another make of car), then maybe the propshaft spline shaft could be modified to take the MS3J001 CV bearing?
http://publications.2evolv.co.uk/?userpath=00000082/00012581/00048044/&page=349
 
I think I have finally got pictures to upload, is this what your propshaft joint looks like (including markings)?
 




 
 

My tail shaft is different. It has green stripe and two orange stripes as well as a yellow dot. It matches the shaft I have on my running Capri which doesn't appear to have been repainted at any time.

I don't recognise the shaft in your pictures. Did you pull it off a car you knew?

It came with a bunch of capri parts I got hold of, so there may be a chance it was off another Ford or later Capri, but I was told it was Capri.  There are a few different 2 piece shaft setups, including one with a centre uni joint rather than a CV.
 
I'd be interested in some photos of what you have there.

I have a tail shaft which I believe came off a 4 cyl that I wrecked years ago which has the thrird uni in the middle in place of the CV joint. It has different colour factory paint markings to the two tailshafts that I have.
 
Not sure how to upload photos but will work it out and post some tonight hopefully.
 
I'm chasing up Hardy Spicer re the GKN brand CV's which they apparently sell.
 
Cheers

No luck with uploading photos. The home computer died whilst starting so off to buy a new one plus retrieve hard drive contents which includes all my Capri resto files and info. Bugger!