For interested 50¢ collectors, I'll set out a list of which coins in Rusty's pictures are NCLT.

Pages 1-3: 1986, 1987, 1989, 1990 & 1992 = NCLT

Pages 4-5: 2002 Accession, 2003 Coronation, 2005 CoA, 2006 Royal Visit, 2006 80th Birthday, all 16 x 2006 Commonwealth Games, 2007 Diamond Wedding Anniversary (not pictured yet) = all NCLT. 

I think that makes 47 coins that have gone into circulation so far, incl the 2000 Incused Millennium. 

2007 CoA hasn't showed up yet, currently available in Mint & Proof sets.

I've found quite a few proof coins in circulation.  I can't see that there's anything special about them after they've been kicked around for a number of years. 
I don't keep them any more.

As an Aussie, I love all the US Statehood Quarters. Don't have any special fondness for a particular one, just love 'em all equally. 

scottishmoney, If you like the coin posted by tyjulie, it's been offered to you & as they're not meant to be in circulation, it's deemed to be a pretty 'good' find. Issue price was only $2, but in my opinion, it's worth having.

CoinCrusader, Are you still after any 20¢ & 50¢ for your sets? Let us know & we might be able to get them finilased for you, so you'll be able to get started on the 10¢'s. 

What are you still missing from these 2 sets?  If they are circulation issues, I may be able to help out.