This is interesting, well it is to me.
When I had the Emco copy I thought about a power X feed but the problem would be getting a powerful enough motor to wind the head back up. Then I thoiugh, why not use a gas ram, like the ones on the tailgate of a hatchback.
Well, gesss what, there is a gas ram inside the column
Thought it was easy to wind up 
However, I am at the point of removing the column but I need to get the lower end of the gass ram of the ball fixing. Do you think it will be the same as a car and a push it over the ball and therefore just need to prise it away from the ball?