This is a very niche area and perhaps related to local history rather than family history.
My cousin, who is the curator of one of the Royal Navy museums, is trying to find details of a facility in Moray which may have produced radio valves during WW2. These were produced under military CV codings rather than the civilian valve type numbers.
I have attached the link below for anyone who wants to see the full context but does anyone know of such a factory/production facility in the area at that time.
It's a real shot in the dark that someone might know something but let's see what's out there.
I noticed this
X MOV, Springvale, pre Oct 1951
Y MOV, Moray, pre April 1945
YA Leigh Electronics, Havant
Seems to suggest there was a Marconi Osram Valves plant in Moray, never heard on one.
https://mullard.org/blogs/news/83886851-cv-numbers-and-uk-military-date-and-factory-codes