The CV8732 looks to be another variant of the EF91 design. The nearest equivalent is the 6064 special quality valve that is also closely related to the CV4014 and thus the M8083.
The M8083 has a more rugged build than the EF91 and was designed for operation in areas of vibration especially aircraft.
This CV8732 has the distinctive blue band of the Mullard / Philips production used to prevent a release of gas from the glass that would shorten the valve's life.
Haltron were an exporter of valves not a manufacturer.
The open structure with two small strap connected plates for the anode and three wire grids.
Here the three grids can be seen clearly. The control grid is wound on copper supports and like the screen grid passes flat across the cathode. The suppressor grid is an open pitch helix.
The thin glass tube envelope is 18 mm in diameter and, excluding the B7G base pins, is 46 mm tall.
