Here we go, sir:
This is the 1990 Allison & Busby paperback. Feel free to use this on Violent World of Parker; or if you hang on till tomorrow, I'll do a better pic and you can have that instead (this one's a bit crap). If you look through the posts on here from the last few months you might find some other covers you're missing too; I've got a couple of Coronet printings of The Rare Coin Score that came after the one you have up, f'r instance, and a first Coronet printing of The Green Eagle Score, which has a similar cover to your Coronet Rare Coin. If you want better images of any of those, lemme know.
(If anyone's confused over what the hell this post's about, see comments here.)