Telewest don't have a 1000 Phase 1b.
They have the 1010T Phase 1b.
The real models are DiTV1000 Phase 1b and Di1010T Phase 1b, maybe with some hyphens somewhere, I don't remember.
They are the same hardware-wise and can run and update in C&W or TW areas.
As VoD requires some interaction with the headend neither work with it at the moment without certain risk.