Jan,
I agree with Mike that the cage would be a simple construction with some strip styrene. Take note of this inside and outside layering as this looks quite obvious.
As for the generator, there is not much of a shot here in this pic. But, go out to the local hardware shop, look in the parts box, and make something close to the effects of the picture and what you saw in the hardware shops.
Perhaps someone else will have some better pics to post to help in this construction.
Dave