Fairey propeller spinner

Not sure that spinner is the correct term as it is just the lower section and back plate.

For a two blade propeller.

Several F8 Fairey stamps.

Part numbers 3B and B66642 and B66643

8 holes but bigger/wider hole dia  than my Gipsy Major hub.

Any idea as to what it is from?

The numbering system on British props does not seem to include this number