Dunlop balls 1907 - c2000... There are many different types of Dunlops some of which were short lived and others like the legendary Dunlop 65 which still exists today. Famous titles include: The Dunlop Junior, Manor, Warwick, Nimble, Goblin, Blue Flash and the most famous of all the 65 and the Maxfli.
Most of the main types of Dunlop balls can be seen in the following pages. Many of these I have in my own collection, others I have found on web searches from auctions and alike (click on any image to see full size and to get some extra details).  
Scarce or even rare Dunlop balls? I guess it's impossible these days to still find full boxes for many of the earliest titles however single used balls of everything must still exist.... possibly even a few wrapped balls from everything ever made. In my 40 years of collecting and researching I would suggest the wrapped Dunlop S, I saw 20 odd years ago must be the rarest... I've never yet seen a used one. There are balls from 1922 which I've never seen either.