The KTW62 is a variable-mu IF kinkless tetrode of the 6K7 class but with slightly more gain. Thousands were supplied during WWII with the KTW62 used in the CR100.
The Marconi paper brand label.
The top screen with the tops of the grid supports. The inner grids are notched for the wire and the outer supports are plain as these support the beam plates. The control grid is taken to the top cap and is wound on copper supports.
The classic envelope is 38 mm in diameter and, excluding the IO base pins, is 103 mm tall.
References: Data-sheet, 1040 & 1043. Type KTW62 was first introduced in 1939. See also1939 adverts.