Need of assistance..

For the past year I have been trying to find out serial numbers belonging to a Spitfire Mk.Vb (code lettering QJ-G) that was flown by Geoffrey Wellum of the 92nd Sqn. I know he flew QJ-K serial # K9998 in a Mk.I. I also know there is another Spitfire code QJ-G serial # X4330 but that was of Johnnie Johnson of 616th Sqn. Is it possible he flew the same aircraft in Malta later in the war? Another tidbit fact I found out that both the 92nd Sqn. and 616th Sqn. do use QJ codes. I even tried the Spitfire Forums site and gotten no bites there since August 2013.