A hinging frame was built out of 30mm x 3 box section and temporarily clad with 2mm plywood. The plywood will be replaced with aluminum tread plate sometime in the near future. The whole structure, including the hinge, is mounted on 30mm rubber blocks to try and reduce vibration and get more accurate signals from the GPS antennae, which will be mounted on the top surface. The hinge itself ended up being more complicated than anticipated as an extra rubber mounted was needed in the horizontal plane. The structure is not unduly heavy, but to get easy access to the oil dip stick and engine cooling system, an simple electrical actuator might be a good idea - no need for quadrature encoders - just electrical end stops to prevent high stall currents at each end of travel.