Hydraulic copying attachments were widely used until the 1970s as a cheap and efficient way of mass-producing, with unskilled labour, small batches of components with simple profiles. Harrison offered a conversion kit for most of their lathes but preferred customers to buy the unit ready installed on lathes of 11-inch swing and above. The device did not interfere with ordinary turning - and a lathe so equipped was every bit as versatile as one without the accessory.
Some lathes had the tank and pump unit fastened to the back of the lathe and some to the tailstock end but much more common was for the unit to be supplied as a separate item, allowing the operator greater choice  as to its positioning.