Hi,
Stephen Pollock-Hill very kindly showed me the moulds for the centrifugally made Dartington bowls, which are still held at Nazeing.
Of course, there are the large pieces made by Wood Brothers for Dartington to Frank Thrower designs, in 1978 for 6 months, which were therefore outsourced as well - see page 80 of the Smithson book.
Nigel