Around 2012-2013, there was an pilot of Hey Duggee called "Chop Chop!",
The differences were, Roly was a pig, Norrie was a wombat, Happy was originally Pov, Betty Was originally Iddy, Happy's looks are remained same with Tag, Bertie was originally a main character and Duggee still existed.
Tag and POV stayed the same in the pilot, but footage has been found so far.