Thanks for looking in, and the comments.
I've added to the Stub, just haven't attached it yet.
In photo 1 you can see how thick the back of the oil cooler rad is and I've thinned it in photo 2.
In photo 3 I've used a PE saw and then flat jaw pliers to open the cowl flaps. I put some CA glue in the crack created when bending them open on the inside to support them. Worked a treat.
In photo 4 Ive added a stick of styrene between some of the rear cylinders. This is because I eliminated the support for the cowling when I opened the flaps. Now I can fit the sticks and attach the cowling to these to make an appropriate gap at the back.
Scratch building can be fun.............! It's like being an airframe shop......