We can find little information on this exhibit. The filament rating indicates that this is a battery valve and so the anode voltage is probably around 120 Volts maximum and 90 Volts is probably the HT used in practice.
Lustrolux were a small British company who made valves from 1926 until the early 1930's.
The interior reveals a vertical anode above the pinch.
A closer look. The support on the right goes to the top of the filament indicating a single strand. The helical grid can just be seen at the lower end of the anode.
The balloon envelope is 44 mm in diameter, and excluding the B4 base pins is 98 mm tall.
References: Data-sheet, 1043 & 1004. Type 210LF was first introduced in 1929. See also1929 adverts.
