Pratt Burnerd 100mm Chuck | Model Engineer
Its about five years ago, so things might have changed, but I bought a P-B chuck from a well known chuck specialist, integral thread for Myford, had to be returned, as did it's replacement. Ended up paying difference for a Bison which is excellent and has retained it's accuracy. From our conversation at the time normal accuracy P-B chucks are made by the same maker as TOS, Griptrue chucks were made in the UK. I've got a NOS Griptrue Myford chuck that I found unopened in a cupboard at work and was given, dates from 1973, which can be adjusted to repeat very accurately at a set size, but if use...
Source: model-engineer.co.uk