Done and worked out well,... apart from some overspray that floated over the car and settled on the windows. A quick wipe over soon removed this,.. but heart stopping.
I ended up buying (and don't laugh) some radiator spray paint from B&Q.
I figured, it will withstand heat from the engine and be water proof, as it happened, was a pretty good colour match too
Went on good with about 5 light coats and 3hrs between coats. Considering its on the inside of the bonnet, I doubt anyone will notice it was painted with a rattle can.
I'm happy with the results.
http://www.mkivsupra.net/vbb/showthread.php?311151-PICS-Supras-out-from-hibernation-A-few-jobs-done-plus-a-good-clean&p=3908093#post3908093