I chose the SIKU Krampe Half-Pipe Trailer for conversion simply because of the location of the cylinder. The location at the front of the model leaves a lot of room to add a screw mechanism and still leaves space under the model to hide the electronics.
The model is quite simple electronically, it just has a micro controller which operates the motor with control purely in the hands of the operator i.e. no limit switches. This model was intended to be the test bed for a generic trailer code which I will use from now on every model I make in order to keep things simple.