The VR107 was a pre CV specification from the RAF. It was later renamed the CV1107 and is a heptode frequency changer based on the 15D2. The base cap also has the old stores code of 10E/383.
The 13 Volt heater in the 15D2 was designed for series heater chains - I wonder if it was also used on vehicle 12 Volt vehicle batteries.
The grid wires extend below the anode. The multiple heater strands can also be seen.
The NAPL 102 looks to be an acceptance testing centre or stores.
VR stands for Valve Receiving, AM and Crown indicate the UK Air Ministry.
The top mica showing the screening grids strapped together, the plain rods acting as the local oscillator anode and the signal grid connected to the top cap.
