Hurricane info needed

I was hoping some of you might help me with the individual histories of the following Hurricanes. They are:
Z4575
Z4607
Z4617
Z4631
Z4639

All of them were from spring 1941 until December 1941 part of 1423 fighter flight at RAF Station Reykjavik. The only thing I do know is that Z4607 crashed on the slopes of Mount Esja on the 23rd of September 1941, killing the pilot Sgt. H.A. Werrells. I do have the individual aircraft letter for most of them from a photograph, but an extra bonus would be to know the two letter Unit Code for 1423 Fighter Flight while stationed at Reykjavik.

Thanks for your time.