hi euan, you can still get the levers think they have been re made, don't know the quality,
their listed for a ford capri, as I think late mk1 capris and cortina 1600E cars used the same systems, escort mexico too I think.
they come up on ebay, theres some on now item no 181382142554, the little tooth adjusters are also used on the aforementioned cars and they come up too but are expensive.
The right hand ones are still available from rimmers but not the left, you`ll` have to look second hand or as said before they do come up.
I have bought a couple of spares before for my spares box.
I thought about changing mine over to the manual system, but you cant get the brake backplates now to do this change.
I think ang classic parts also does the levers their about £46.00 for the pair.