Is there any clue what type of propeller could have the Bristol F.2b serial number F 4409 built in British & Colonial Aeroplane Co. Ltd.? It was powered by RR Falcon III engine. There is no known photograph of this plane but maybe some other sources can solve this prop-mystery.

With some certainty, yes. There were no left handed (left turning)RR Falcon III engines. That means its either the two or four bladed right hand turning propeller. F4409 was right in the middle of a 700 airframe contract. (F4271 - F.4970) These are late war production serials and the 4 bladed prop seems to have gone from main production use to being relegated to a replacement item. The two bladed seems far more prevalent. In the photo image below the right hand two bladed propellor is the one at left. Though I went with a clear coat over the laminations most were dark stained or shellaced a single red brown colour. Photo images of the real aircraft from this production batch bears this out.

If you check This feature of the Shuttleworth collection photos 55 and 56 show a Bristol F.2B 'Biff' prop. while photo 25 show one fitted.

HTH

Many thanks guys, most apreciated clues.