Wilma - in addition to the above, your friend will probably find the MoD publication scheme section useful -
https://www.gov.uk/government/organi...ication-scheme
Work your way through the various permutations for what is sought.
In respect of medals, decorations, citations, squadron histories etc there are several Highly Respected Gentlemen around here who have Considerable Expert Knowledge. (Not me btw.) LFH