The KT32 was designed as an audio output device in universal sets with a 300 mA heater chain. The 3.5 Watt output was to be had with an anode load of 1,300 Ohms.
The original brand label has been lost.
The base of the anode box showing the rectangular cathode tube with four heater strands within. The control grid supports are copper.
The classic envelope is 45 mm in diameter and, excluding the IO base pins, is 108 mm tall.
References: Data-sheet, 1040 & 1043. Type KT32 was first introduced in 1937. See also1937 adverts.