Propeller ID Further info

[David Bathe]

Dear all. I have a wooden propeller in my procession, a beautiful object that I'm collecting in-depth information on.

From the pictures you can see the prop is marked:
A.D. 644. R.H
130. H.P. CLERGET
D.2660 . P 2650
G 297 NO 95
I know its produced for a Sopwith Camel, the production date, Batch number, Lot number and the Pitch... but the eagle eyed will notice an anomaly: The diameter specification is larger than standard 2590mm and this isn't a mistake. I'm producing accurate engineering line drawings of the prop and I've carried out extensive measurements of the complete jigged propeller and that figure is correct.

Im guessing the extra dimension was ordered to combat the engine slightly over reving in certain unusual combat conditions, cold weather operation, very low level combat sorties etc. if there is anyone out there with some additional or ideas I'm really looking forward to hearing your thoughts. It’s has the experts stumped I’ll tell you.