Type 9003 is electrically equivalent to 'acorn' type 956 but re-engineered to B7G dimensions. The valve is classed as a vari-mu UHF receiving pentode.
The design dates to 1943 but B7G based valves were not made in the UK until the late 1940's.
This American made valve has both the commercial designation of 9003 and the government procurement code of VT-203.
The 9003 and other lettering is printed onto the glass. The inner coating obscures the electrodes. SeeVT-203 for a version with a clear glass envelope.
Looking at the base the dark anode can be seen within the outer screen.
The thin glass tube envelope is 18 mm in diameter and, excluding the B7G base pins, is 38 mm tall.
Reference: Data-sheet. Type 9003 was first introduced in 1943. See also1943 adverts.
