Superb uniform shots above. I have a button off my grandfather's RFC uniform, only issued for what, about 4 years?
Even scarcer are the RNAS buttons which followed the naval pattern with the rope around the rim. I believe these were sometimes worn on early RAF uniforms, although not on the examples illustrated by
iRaven above.
https://www.google.co.uk/search?q=rn...w=1366&bih=662