This set is a very early seven (7) all 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!
Seven (yes seven) triodes
All-triode: self-oscillating "autodyne" mixer followed by three IF stages (90-110 kc/s); triode detector and two AF amplifiers.