Great picture and it does raise some interesting questions.
What dates it to the Battle of France?
It is interesting in that it does appear to have wooden blades on the propeller.
AFAIK, the Rotol C/S had metal blades and was not adopted as it did not improve performance over the 2 speed Hamilton.
At least that is what the RAE says and that conclusion is backed up by the data on Williams site. This is actually the correct use of performance comparisons too! We can see the performance improvements brought about by the different configurations and propellers.
http://www.wwiiaircraftperformance.o...rricane-I.html
The 2 speed DH is a 3 bladed hub. The same hub was later reworked to upgrade to a C/S. I would think most likely this is a 2 speed DH. The question arises about the wooden blades.
http://www.wwiiaircraftperformance.o...ane/l1547.html
I do know that both DH and Rotol built wooden propellers for testing purposes.
Interesting photo and I look forward to learning more about it.