Derek,

I loved that engine back in the 60's. I Had a MK2 and had it on a Charles Mackey designed Red wing. It was a C/L delta wing with the engine put out off centre on the outboard wing. I used that engine because it was the engine used on the designers model and I had it. It wasn't the most potent engine but it was reliable as I recall. Add to the fact that I always liked FROG engines having a 1.49 vibramatic, the 50, and the Frog 2.49 and 3.5. Alas it is no more it got traded on a model to someone else for something that I can't even remember what.
As to the Red Wing a fellow modeller in OZ was good enough to forward a copy of the plans to me and I cut a kit. Haven't got around to build it yet but it is still on my bucket list to do before I'm history.

Derek,

Here is a picture of Charles Mackey and the RedWing Delta