The VR101 is a double-diode-triode that is directly equivalent to M-OV type MHLD6 and dates from 1940. This RAF receiving valve would have been used in superhet receivers as signal and AGC detector plus first audio stage.
The VR101 is pin-compatible with type DL63 but the heater current of the MHLD6 is 0.65 Amp as opposed to 0.3 Amp for the DL63.
The triode section is at the top and here is seen end on.
The inner coating masks the rest of the electrodes but one can just make out the box like structure below the triode. This structure contains the diode anodes. Sometimes each side of the box is a separate anode and in other cases the box is one anode with two rods within forming the second anode.
The classic envelope is 38 mm in diameter and, excluding the IO base pins, is 99 mm tall.
References: Datasheet & 1043. Type VR101 was first introduced in 1939.