Biglips - We had this with DD when she was little - used to cry when it was finishing and was inconsolable - DS now is the same and I have to watch 'Pippin' most days at least 10 times - before he goes to bed - we have them on DVD now only because we burnt it after Sky+ing them all.
I did ring the BBC all those years ago - about 4 years to ask if I could buy it and they said they had no intention of releasing it.
Can you not tape it? If you can't find it I will burn the ones we have on our Sky+ onto a DVD for you - at the moment we have fish, bricks, pencils and boots!! Maybe some more but will have to have a look - if they are still showing them on Cbeebies I will sky+ those and burn them onto t disk for you too.