Thanks for all the replies they have been really useful. I am off to Kew on Saturday to have a look at the sources you have helped me with.
Just as a follow on question, my uncle was a fully qualified telegraphist in civvy street and his docs seem to indicate that he spent the first year in the RAF as a W. Oper (Wireless Operater I am assuming). But then remustered to Armourer. Does anyone know if armourers where paid more and was it a job which was a volunteer only post?
Thanks again and I will update you with any more info I get my hands on.
CC