This set is a very early 7-triode superhet produced in 1928/9 by Selector
A luxury battery operated set costing £54 12s 0d in the late twenties - equivalent to around £2,500 today!
All-triode: self-oscillating "autodyne" mixer followed by three IF stages (90-110 kc/s); triode detector and two AF amplifiers.
Two waveband "short" (now called medium) and long. Works well with internal frame aerial.