Ditto Eagle's comment, and NC, I'm not sure about the antenna mast, but I'm almost certain the wing cannon bulges should be removed.
As far as I know PR Spits all used the 'Bowser wing', that is, a wing devoid of guns, and with leading edge fuel tanks to improve range. Sorry, I can't be more specific, but the squadron signal 'Spitfire in Action' is a little hazy when it comes to details,- frustrating for me too, one of my projects is a PR.XIX.