Villiers didn't make identification of their engines an easy task!! Villiers stopped using AAA for their postwar 9D, and included them in their complicated postwar system which you need to read Bacon extensively to understand. In fact he even makes a small error claiming Norman used the prewar and wartime 9D prefix of AAA. It is very good but he makes it very clear he could not find a complete list of all Villiers identification numbers and this is one of those that is'nt in his book. The usual book people refer to for this type of information is Villiers Singles & Twins by Roy Bacon.
The prefix 364 on the engine denotes an engine supplied to Norman in the period 1946-48'
