Although there is not a lot of information about my father, Philip Radcliffe-Evans, and the Brunswick Printers there is some on the internet. My father died in 1992, so left no trace on line, and for all his post-war life, the maps and documents, photographs etc., remained in a cardboard box in a drawer, only to be taken out very. very occasionally.
After he died, I donated a set of the original maps to the British Library where they are now curated and where they have had an online presence for the last 15 years or so. The Brunswick Printers also feature on a website run by Keith Morley called The Escape Line which focuses on escape and evasion experiences in WWII. Both these give some further back ground and maybe of interest.