use some ready mixed laquer diluted further with cellulose and a spot of black paint to spay over the bonnet - didn't give the transparent black effect I was aiming for as obvioulsy not put in enough paint but not gonna mess anymore.
Fitted an ali plate above the exhaust manifold, held 10 mm away by screws and spacers and it makes a lot of difference; not measure it bu would say 10 or 20 C - previoulsy I could not keep my hand on the bonnet but now can
So onwards with the radiussing nonsense for SVA...