It's a shame this RAF skin no longer seems to be available. Looks like it could have been an easy conversion for gaab also.
http://www.sim-outhouse.com/sohforums/showthread.php/70788-Beech-D-18-Royal-Air-Force-FSX-Native-zip
http://www.sim-outhouse.com/sohforums/showthread.php/70788-Beech-D-18-Royal-Air-Force-FSX-Native-zip