The identificatio 110E/274A is an old UK military stores code and nt a Type designation. No actual designation appears on the valve.
The intended user is quite clear from the Air Ministry logo printed on the base.
The number of grids indicate that this is a heptode mixer aka pentagrid converter. The signal grid g3 is taken to the top cap. The fine wire spring and single strand filament indicates that this was a battery valve.
The top mica and grid supports. G2 is just two slightly thicker rods and acts as the oscillator anode for this self oscillating mixer.
The wide glass tube envelope is 29 mm in diameter, and excluding the IO base pins is 89 mm tall.
Updated October 29, 2015.