Hi Mary and welcome to the forum, there are some photos here of 40 sqd which may be of interest but most of them seem to be after the date you mentioned your father was shot down. Do you have his service records? they are a mine of information. I started looking for info on my late father a couple of years ago and can assure you it is a worthwhile search, though at times frustrating the end result is well worth it.
Good luck with your research. Regards Robert.