Davey Boy
When I was at the AIDU printing works at Northolt a couple of years ago there were OS maps coming off the press with powerline info on them. They print all sorts of stuff there from BBMF Brochures, to RAF Sports magazines to Sqn Anniversary literature to maps of various shapes and sizes.
Don't forget that Feltham and AIDU come under the JAGO and ICG banner under Defence Intelligence.
LJ