I picked up 5 larger coins for $1 each at a coin show a couple weekends ago. They were all about 38mm, but they were in some old vinyl coin flips. I figured for a buck each I would grab them, and see if I could get the sticky green film off. I rolled qtips with acetone on them across the coins, and the green gunk came off pretty well.
Two of them are in the link that you have in this thread.
I really like the British crown commemoratives. There are a lot of cool coins in it. I only have a few of them but I usually pick them up if I see them for a good price.