Hey Jack excited to see your progress on this.. the 2002 TM is an amazing piece of design and workmanship.
I found some rough dimensions of the barbers chair that might be helpful as far as scaling things goes.
Keeping in mind the chair for the 2002 TM was not an original Berninghaus barbers chair but a production replica, in tribute to the one used in the 1966 TM (which apparently was originally used in Chaplin's 'The Great Dictator') so the 2002 prop makers may not have made theirs exactly to the same dimensions.
The pedestal and footrest were removed of course and the padded piece used as the headrest in the 1966 chair as replicated in 2002.
Some additional info on the chair in case it's helpful
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