"If there is a change in the shape of Orion's belt it must be due to Proper Motion of the stars themselves, so Hancock's idea of change due to precession is a load of bollocks."

Exactly my point. And if they are changing, how do we know? We can do the doppler thing for motion away from us but do stars go apparently sideways and how long would it take for us to detect it. Is such a thing shown on the astronomy software?
Oh crikey I hope this isn't going to get into relativity.