Thanks Andy.
I might have to strip the paint from the prop spinner - painted it over six hours ago, and it's still tacky. I'll leave it overnight and see what it's like tomorrow before deciding.
The paint was mixed with yellow (new tin) and an old tin of Humbrol; Forest Green, to give the 'woodpecker' green shade, and I think the oils were separating from the green paint.
Back some time tomorrow.