Mystery Propeller

[Mtskull]

I have just seen this propeller on eBay.
It is marked:

BABY SEAPLANE.
A.D. 500. RH. 100. HP.
MONOSOUPAPE. GNOME.
DRG. 500.

One would have thought that this would be sufficient information to identify it but it isn’t as straightforward as that.
The seller states that this is from an F.E.8 aircraft. The engine is correct and the diameter is identical but this is clearly a Right Hand tractor, not pusher propeller, so cannot be from an F.E.8.
The Gnome Monosoupape engine clearly dates this to around the WW1 era and the words “Baby Seaplane” ought give a clue.
Having said that, there were at least four aircraft designated “Baby” during that era!
The Supermarine Baby was a pusher and used a Napier Lion and the Felixstowe Porte Baby used Rolls-Royce Eagles, so I think these can be safely ruled out.
The Sopwith Baby and its development, the Fairey Hamble Baby, both used Clerget engines and every photo I can find shows 2-bladed propellers.
The Sopwith Schneider seaplane from which the Baby was developed used the 100 HP Gnome but was it ever referred to as the “Baby” and did it ever use a 4-blade propeller?

Can anybody shed any light on this?

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[Dbahnson]

There are two listings for AD500, one has a (256) suffix and is right hand rotation, the other a (257) suffix is left hand rotation. Both are four-blade and both are listed for the 100 HP Gnome but the right hand model is only listed for the Sopwith Baby, so that seems to be a valid match for this one. (The left hand model is also listed as a tractor, but for the "FBA Flying Boat". Since all of the FBA flying boats were pushers, I presume that the listing of it as a tractor for the Gnome is in error. )

[Mtskull]

Many thanks, DB.
I think we can safely conclude that at least one example of the Sopwith Baby (a development prototype maybe?) was fitted with Gnome engine and 4 blade propeller.