Some history, Dynatron sold to Ekco 1954, the Hacker bros stayed until 1959 before forming Hacker Radio.
http://www.dynatronmuseum.org.uk/History.htm
They probably needed the mains transformer to power the push pull audio stage, it’s a large TX so it probably powers other parts of the set. The tuner, Metrosil and LOPTX are of Ekco stock.
https://www.vintage-radio.net/forum/...d.php?t=108863