Got the 2 x 20 tonne air over hydraulic jacks hanging in place today. I've left some of the threaded stem on the jacks accessible so I can adjust to get the top and bottom tools parallel.
I've only got a small lathe so the bits that go around the knob on top of the jack screw were slow going. I made them a week ago.
Each jack can slide side to side. Not sure if I'll ever need to move them but seemed like a good thing to allow for now rather than wish I had later.