just for the sake of science, you can scroll down here and see what a Watts propeller looks like (and how long it is)
http://www.spitfirespares.com/spitfi...ropellors.html
I thought they could be wooden propeller blades from a 4 blades prop, but the real ones are 145cm long, even if more similar in shape.
http://www.tennants.co.uk/Catalogue/Lots/121794.aspx
they're probably props for some other British aircraft, but God knows what and surely not worth 2 grand!