Yes MK1 defo had hydrailic, later MK1 as earlky ones were cable(not 100% sure)
XR4i converted easy to HYDRAULIC with kit of brakets made by MAGNUM ENGINEERING, but easy to make yourself, just fiddly with upside down welding, and weld drops in your ears make you do a funny dance!!
The master cyl was mounted oin the bracket next to pedal with remote reservoir and pipe on bulkhead panel near fuse box.
The m/cylinder was from a sherpa van as was correct size for the slave cylinder at gearbox, use a slightly biiger bore m/cyl as you can always reduce travel at clucth end, if to small you won't shove enough fluid to operate on each push of pedal.
tabetha