So with this in mind, the usual solutions that I've found to fit power steering to a 101 are not doable. So I opted to fit a steering from a Land Rover Santana. Now a couple of years ago those things where easy to find, but now, they are getting very rare ! Took me this long to get one:
Basically you have a double action cylinder, and a control valve in between the steering columm
I also had a new cylinder custom made because is was afraid that the 14 mm rod from the Santana wouldn't be up to the task of turning those big 101 tyres.
So now I'm in the process of fitting the cylinder to the car, for that purpose I made this
It attaches to the front diff. I'm not happy with this, but it will serve for the time being.