Great stuff. I've often wondered what these scale engines would be like, if it was/is possible to mount them in a scale aircraft, for example, a 1/5th scale Merlin in the same scale Spitfire. I remember seeing a (I think) 1/3rd scale Merlin running at the Model Engineering exhibition, back in the early 1970's - incredible; it even had a 'scale' exhaust sound !!