Need help identifying this wooden military box!

Hope this is the correct fourm, so here goes. I recently came across this old wooden box at a good friend of mine's shop and he has no idea what it's for. I have attached a few pictures so if anyone knows what it is or can share any info we would be grateful.

https://www.milsurps.com/images/impo...RVIEL057-1.jpg
https://www.milsurps.com/images/impo...RVIEL055-1.jpg

Vehicle transport box for Mark IX* * * Discharger Cup Pistols?

(What anyone not British would call the smoke discharger pots on a Tank or APC?)

Very interesting artifact. First I have ever seen, anyway.

Thank you.

Flare pistol case ?