best opportunity would be to go to football badge fairs
programme/badge/ephemera fairs - and be patient - there are so many badge collectors who only collect 'Miller Ball' badges that you have to wait for them to come across an upgrade on the quality of another inorder to pass theirs on - the AFBC annual meet was last month down in derbyshire, but there are football memorabilia fairs in newcastle, all across lancashire and of course birmingham and london - of course prices are rising for rare badges (at some rate) - hence why i said "dont get ripped off"