Yes, it's a very good article, several pages long. There's the odd mistake but I use it as a regular reference. It's a shame there's no other book since Peck that goes into Copper proofs/patterns in depth - there are references to articles on things like Soho patterns that are apparently very useful but these are often in defunct publications or BNJ (so maybe on the web).
 
	I haven't got a decent scanner unfortunately, all I can suggest is that if you're visiting Spinks (DNW might have it as well) they should be able to provide you with a photocopy (or Secret Santa's reply which I've just seen).
 
	I had a look at my P1323 proof KP30 last night and you're right, it has got the incuse curl. I find it hard to tell without having a strong mag. glass to hand, even then I was getting a bit cross-eyed! Raised/incuse can give an optical illusion of the other way round at times.