Some photos of an Ariel in RAF livery taken at the Kempton Park Classic Bike show
http://www.fielder-rowe.freeserve.co...AF-Ariel-1.jpg
http://www.fielder-rowe.freeserve.co...AF-Ariel-2.jpg
http://www.fielder-rowe.freeserve.co...AF-Ariel-3.jpg
http://www.fielder-rowe.freeserve.co...AF-Ariel-4.jpg
http://www.fielder-rowe.freeserve.co...AF-Ariel-5.jpg
As suspected, no roundel, just stencilling on the tank and white blackout markings on the muguard tips.
Timing cover and chaincase are finished in RAF blue.
Hope this helps. Sorry about the pictures, lighting was poor.
Mark.