Prop i/d
It looks like the sction through the root end (look at the way the laminations run) of a post WW1 prop. Looking at the size it could be from one of the big 1930’s types such as Kestrel or Pagasus-powered aircraft.
The A could signify the logo for the Airscrew manufacturing company (was it called Airscrews Ltd?) It looks like an A inside a letter C, but I don’t know enough about the range or types they made to speculate further.
Not much to go on, I know, but it might take this a little further.
Anon.