WW2 Service Competitor Watch

My husband has been wearing a Service Competitor watch for many years. It belonged to my father who passed away and left the watch to me I gave it to my hubby 20 years ago and he wears it every day. He wants me to put it on CW to find a date of manufacture. It has Made in Gt Britain printed on the bottom of the dial. We last serviced the watch in 1994 and it still keeps perfect time. The watch is pretty unusual as the face is white it also has a duel 24 hour clock on the top and roman numerals inside. The strap is original and fits any wrist as it clips to the links. The face is 1.1/4" in diameter. Would anyone be able to date the watch? Thanks.