S&S Test Club?

[29Brighton]

New member and first post. I am a bit of an aviation enthusiast and mentioned to my wife a few months back that I wouldn’t mind one day owning a vintage propeller. On my recent birthday she surprised me with a behemoth beautiful object that looked like a two blade wooden prop but not quite. From my google research, I am quite certain it is a “test club” (a term I had never heard of before). The seller said his father found it in the 1980’s in what had been an old engine repair shop on Sea Island, near Vancouver International Airport. The debossed markings on the wood are as follows:
Two circular stamps with “S&S Ltd.” (which I believe was a prop company from Winnipeg)
Following stamped lettering: DIA 65”; PIT 80’4”; H.P. 225; R.P.M 2150; Jacobs L4; Nov 1941
(what is interesting is that some of the original stamped lettering was XX’d out but you can read what was under the X’s which was originally DIA 71”; PIT 80’; H.P. 300; R.P.M 2100; Jacobs L6).

My research indicates that the “Jacobs L6/L4” markings relate the Jacobs Aircraft Engine Company (1926-1956) and two of its model numbers.

This beautiful “object” is very heavy (I would estimate 75 pounds) and the steel hub is fully intact with all bolts and nuts.

I have scoured the internet and have not found any similar two blade test clubs of this vintage.

I would really appreciate some comments from the numerous experts on this forum as to what my wife has given to me. (it’s not the prop I would have bought for myself, but I really love it and think that it may have some historical significance). Thanks.

[Dbahnson]

I think it's much more likely that it was a certifcated prop that had tip damage and was cut down, perhaps to use as a test club, but the test clubs I've seen or owned all had pitch angle that was the same along the whole length of the blade.

[29Brighton]

Dbahnson, except where it transitions at the hub, the pitch angle is the same along each blade. The diameter is exactly 65" as stated on the markings.

[Dbahnson]

OK, that's a little hard to see from the photo, but it WAS 71" and is now 65", so three inches have been removed from each blade. I'm not sure why but perhaps it was a test club that was re-configured for another application.

[29Brighton]

Dbahnson, I think you are right about the change in the markings - a reconfiguration from L6(300hp) to L4(225hp) - either that or someone made a mistake when originally applying the lettering and didn't have a delete key! In your experience do you ever see xx'd out lettering on wooden props?