Bit late but for anyone else wondering, the crane is control by a standard mechanical 7-lever valve stack. The stack is inserted into the back window and connects to all the hydraulic rams on the crane with hydraulic hoses. The crane also has a seperate valve on the outside for controlling the hydraulic whinch. The steering boom on the wagon is controlled by the tractor's own integrated two-way valves. This particular model is from somewhere around 1993, so electric joystics weren't really around yet.