Not sure about that Chris, there are photos of 7 and 9 staffel machines with their yellow and white vertical bars plus a Stab machine with Black vertical bar all from the latter part of 1942.
All losses for May to Oct 42 are Bf109F-4's and F-4 Trops for III/JG53
Probably what you are looking at is Bf109G-4's
III/JG53 was pulled out of Africa to Italy in late October 42 ( leaving behind it's F-4 aircraft) and reequipped with the Bf109G-4 Trop and then headed to Sicily.