I have painted it on my 'Green 3' as I had put on the PE panels and I didn't think the decal would go on right. I think it is just a bit of black paint to make the heat damage from the exhausts less noticeable and easier to re-paint rather than trying to cover damage on the camo finish. As Tony said, bit of a personal preference.
The aircraft is looking really good Paul, very sharp build and paint job. Another name for my list of "Who to send my kits to for painting"
Nice to see another one with the spiral on the spinner. Mine had the shorter spiral but I have to say, after reading all the problems putting the
decals on, I was surprised how easily it did go on. I sort of dropped it in place and it fell into position. The secret I think is to paint the spinner with lots of water so it slides easily.