Ross Hydrapower steering explained in old military movie

I tried to figure out how the Ross Hydrpower HP70 works, especially how the turning of the steering wheel is transferred into moving the lever that regulated the oil flow. When searching, came across an old military movie explaining it all, if even a bit long winded.

https://youtu.be/2M8SMeMpQ1M

When you look at the pics in my thread on repairing the PS, you will see that it is exactly the same equipment.

Thank you for posting this, A very informative video to show the lads.