Arm of service markings (there are also Formation markings but these were not used on motorcycles)
seems there was the RAOC as well as the RASC, looking at the pics.
Arm of service markings are approx. 9 1/2 inches high X 8 1/2 inches wide.
They are positioned on each forward end of the fuel tank.
RAOC vertical stripes, blue, red, blue
RASC diagonal, lower left green, upper right red
W.D. Registration Numbers – Motor Cycles
Front numberplates – All dimensions half of those for vehicles.(I put vehicles after)

Rear numberplates – An oblong plate with the number expressed in three lines, e.g.:

0 1

EN

4 6

Dimensions of figures & letters:

Height 2½ inches.

Breadth of every part of each letter or figure 3/8 inch.

Total width taken by each letter or figure 1¾ inches

Space between adjoining figures and between adjoining letters – ½ inch.

Space between lines of letters & figures – ½ inch.

Margins between edge of plate & letters and figures – ½ inch.
W.D. Registration Numbers - Vehicles
Numbers will be inscribed on numberplates in WHITE with BLACK background, in a single line.
Dimensions of letters & numbers:
Height – 3½ inches.
Breadth of every part of each letter or figure – 5/8 inches.
Total width of space taken by each letter or figure - 2½ inches.
Space between original figures & between adjoining letters – ½ inch.
Margins allowed:
Between top of number & top of black surface – ½ inch at least.
Between bottom of number & bottom of black surface – ½ inch at least.
In front & at end of numbers – 1 inch.
Space between the letters & numbers – 1 inch.
Right, I off to sleep now!
Simon.
