Hi Alan,
As far as I now the set originated in the Midands, Gary bought the set from a collector in Kidderminster.
Hi Richard,
The set is a 625 line only receiver. The 26" square corners CRT was introduced late 1970, a year after all three TV services in the UK went colour. According to the Radiomuseum the developer of the A66-120X was Telefunken.
https://www.radiomuseum.org/tubes/tube_a66-120x.html
A 22" dual standard G6 model was announced by Philips in 1968.
DFWB.