G'day Chris,
FX666 CV-Z was one of the last Kittyhawks delivered to 3 Sqn before conversion to Mustangs, it only operated with 3 Sqn for about 3 weeks before xfer to 450 Sqn, hence the mixed up /incorrect text on decal sheet, as far as I know it was the only Kittyhawk to get the blue rudder with southern cross applied, on page 155 of Stewart Wilsons "The Spitfire, Mustang and Kittyhawk in Australian Service" is a picture of the tail presumably of this aircraft.
Also another thing with Kittyhawk IV schemes, very few were in desert scheme, as the Kitty IV's came into Sqn use about the time of the invasion of Italy (were the desert scheme didn'r suit the some were in Desert scheme but the vast majority were in the TLS of Dark Green/Dark Earth over Grey and late delivery aircraft were in std US OD over Neutral Grey, the fixation that all Desert Airforce Kittyhawks must be desert cam gets in the way of reality, I have been informed in fact the 112 Sqn Kittyhawk IV at the RAF Museum in desert scheme is wrong , the fixation with 112 Sqn Shark Mouthed aircraft and desert schemes caused it to be in this scheme , FX760 was in the TLS scheme