That's BeebMaster himself in there, holding onto the sucker stick and gun to demonstrate what the finished product might look like. Of course the final Dalek would have a panel built into the white part to house the gun and arm.

The arm is telescopic and is made out of two cardboard wrapping paper tubes which just happened to fit very snugly one inside the other. At the end is the rubber bit off a sink plunger - just like a real BBC Dalek - affixed to a cork and then inserted into the end of the telescopic arm. It was painted with real black paint.

The gun is a painted piece of broom handle with eight spokes off an old umbrella mounted onto it. I think the spokes were about the right length so we just bent over a short length at each end banged them in the broomstick.