The Stentor Two was introduced by Cossor in 1927. The following year it was re-branded as the 215P and was still listed by Cossor in the mid 1930's by which time the 'New Process' filament was in use and filament consumption was 0.2 A to deliver a greater output.
Cossor also produced a 4 Volt version as the Stentor Four that was later re-branded as the 410P. The version for use with six volt accumulator's was the Stentor Six (later named 610P).
Cossor was a BVA member and inside the distinct 'hat' anode can be seen as the gettering does not reach the base.
The base of the anode and the paper label. The main operating details are on the left. Within the glass can be seen a coil with a central wire. This is possibly the filament tension spring.
In this image the wire grid is just visible within the anode.
The balloon envelope is 45 mm in diameter, and excluding the B4 base pins is 96 mm tall.
References: Data-sheet, 1043 & 1040. Type Stentor Two was first introduced in 1927.