Another long shot, but you could try Aircrew Remembered web site, which might have some details, although it normally covers aircrew lost in action or accidents.
However, Flight Engineer and Radio, or Wireless Op, were two distinct trades, and it's probably unlikely he did both. It's also probable that the Spitfire model was just for interest, as again, it's unlikely he would have been directly involved with Spitfires if serving on a Lancaster squadron.