Need Help: Sensenich Buhl Bull Pup Counter-Rotating Propeller Mystery

[PropArt]

Today I picked up Sensenich Des 755 Wooden Airplane Propeller. According to Sensenich this propeller was used on the Buhl Bull Prop LA-1 and LA-1B.

I have found several photos of the LA-1 but the propeller I have is counter-rotating. I have yet to find a photos of an LA-1B. Anyone have any information on why the propeller I picked up today is counter-rotating?

Here is propeller I picked up

Here is photo of exact propeller des 755 on a Bull Pup LA-1

https://www.deviantart.com/redtail12...m-33-735177219


http://www.chevyasylum.com/cruisin/cruisin2011/20110218/1931%20Buhl%20LA-31%20Bullpup%2001r8.jpg


and here is a video of similar prop on Bull Prop LA-1


This is driving me nuts. Any help would be greatly appreciated in solving the mystery of this backwards propeller.

[PropArt]

Im beginning to think it went on the Curtiss-Wright CW-1 Junior.

Expert Thoughts?

[PropArt]

https://www.youtube.com/watch?v=p3YzpZMgCeU

[Dbahnson]

I think your second guess is most likely correct. I can't think of any reason to engineer a counter-rotating engine on a single engine aircraft, so a pusher application would be the more logical explanation.

Also, from one of your photos it looks as if the nuts on the hub are on the trailing (flatter surface) of the propeller, which fits with the mounting of a pusher prop.

[PropArt]

Thank you Dave for your valuable insight. Always Appreciated!!!!!

Found another image to confirm this.

https://www.skytamer.com/1.2/2004/4121.jpg