The RC Massey 8680 is based on a static SIKU model (No. 3278) which is a relatively cheap model with quite good build quality. The construction of the model suits RC conversion well as it is screwed together and can easily be disassembled. However the model, while a relatively large tractor, doesn’t have a huge amount of space for wiring and electronics. In addition the bonnet does not close tightly to the body of the tractor leaving the plastic engine visible between the bonnet and the body. This means that you can’t simple remove the engine and replace is with electronics, you need to modify the engine to hide the electronics.
The Massey 8680 was the first static model I attempted to convert to radio control and it was a reasonably successful first attempt. It was a test bed for many drive train attempts using motors I had collected over the years and different gear and belt drive arrangements. As a result the model was cut and modified quite a few times before I settled on my final design.