The E2192 is an M-OV development sample and this exhibit has the serial number of 38. The number of grids indicates a pentode. The top is enclosed indicating a screened valve. The E2192 became the commercial Z63.
The top mica connection of the top cap to the control grid copper supports.
From the pinch it can be seen that the anode cylinder is enclosed within an outer screen. The three grids and the oxide coated cathode are clear to see.
The wide glass tube envelope is 29 mm in diameter, and excluding the IO base pins is 87 mm tall.
Reference: Observation. Type E2192 was first introduced in 1937.