I believe the handle grips are now discontinued, my friend has a few of them spare as he used to work for beeb fx and got access to the original casts, so he stocked up on a few relevant parts. The problem is ( budget wise ) that on the original K-9 a couple of the buttons when depressed would stay in a down postition, whilst others would spring back up. He was telling me all about this a couple of days back, but to be completely honest, I really do not like the k-9 prop so I didn't pay much attention.