Great photo, Simon.
A couple of the chaps are wearing Sgt. chevrons. To the best of my knowledge, this was not permitted within the VTC:
'The accepted military ranks and titles will not be used or recognised, and no uniform is to be worn except where necessary for training.' *
Simon - Sgt.jpg
As we know, the VTC had their own cuff lace rank system too:
VTC Ranks.jpg
Also, the drum appears to say '8th' (possibly), before the MKB, and 'Coy' after it. Just an added observation:
AE3A5AEC-009D-4D32-A1B5-8C48D3363DB6.jpg
The buttons appear to be black 'rifles' buttons, but could equally be the so-called 'football' buttons often seen worn on the VTC uniform.
CLNG b4.jpg
Thanks for sharing.
JT
* Source: 'Uniforms of the Volunteers 1914-19', The Journal of the Society for Army Historical research, Autumn 1938, Vol.17, No.67, pp. 163-170.