[Guzzman]

RNR ratings were given a badge of the letters 'RNR' in 1875 and this was at first intended to be worn on the breast, but later moved to the sleeve. This badge was worn throughout the First World War. Variations existed (such as the one issued for members of the Royal Naval Reserve (Trawler Section)) which had the letters 'RNR' above 'T'. The badges worn were the same size as the one you have.

In 1921 it was announced that RNR ratings were to be distinguished by the letter 'R' to be worn on both cuffs. In 1924 this was replaced by the letters 'RNR', but later in the same year it was ordered that the letters were to be worn on the left cuff only. This badge came in a larger and a smaller variant but neither was anywhere near the size of the badge worn during the First World War.

As you say the letters 'FAA' were worn unofficially on the cuff by some Fleet Air Arm ratings. This continued the tradition of wearing the letters 'RNAS' which existed during the First World War. When these badges were found to be being used (in, I think, 1942) , it was decided that no action would be taken against personnel wearing them as it might be bad for morale. Several similar badges were worn during the war, all unofficially, and they were all allowed to be worn until 1948 when all unofficial badges were banned.

Pete