I saw this Ad for a 1962 PYE pedigree on Gumtree Australia.
http://www.gumtree.com.au/s-ad/maryb...tro/1042772442
This set uses the PYE T-21 chassis.
During the life of this model 3 different chassis were used.
Starting with the T-21 chassis, then came the T-23 (hybrid chassis, Introduced in about 1966) & finally the T-26 (fully solid state chassis & had a squarer CRT, Introduced in about 1971)