Hmm. The serial number shows it as the first of only 50 in this serial block built as MkIs. It went to 57 OTU (Operational Training Unit) on 18 July 1941, and then to 27 OTU on September 27 the same year. It was struck off charge following a mid-air collision with X4605, on 16 March 1942.
The code letters shown certainly aren't those of a Fighter Command squadron, and I don't have a listing of all OTU codes, but presume they are from one of the OTU's on which the aircraft served. The shade of the colouring on the nose seems familiar from a B&W photo I've seen somewhere, but whether it was that dull yellow colour, I don't know. The colour might be panels and spinner in primer, or could be a colour used, by an instructor, for formation purposes during training. It seems an unusual choice for a kit markings though. I at first thought the colour might be associated with the Dieppe raid but, apart from the dates not matching, I doubt that yellow would have been used, as it could easily be confused with the yellow ID paint of Luftwaffe aircraft, and all references I've seen for this operation are for white, or white/black panels, stripes or checks on forward areas of fighters.