propeller identiy

[greybeard]

I have a large wooden propeller that I acquired from a co-worker approximately 40 years ago. He thought it was from a WWI plane? My original plan was to refinish it and put a clock in it but never got around to it. I recently learned that some of these are worth more than just a few bucks and am now interested in learning what it might be.
It is 8' 8" long and has an eight hole bolt circle of 8 inches, the bolt holes are 15/32" or 1/2". The center bore is 3" or 3 1/16". The ends have a metal cladding on them, I think it may be brass.
The only info i can find on the face of the hub is a number 1478 and the letters F.O.R. There appears to be something else just above the letters F.O.R., but I can't determine what it might be. The same number 1478 along with 88x5.90 is stamped on the outside radius of the hub.
The face of the hub area is mortised out 11/16" deep by 10" in diameter. Also, on the same side within the 11/16" mortised area and inside the bolt circle there is a much deeper mortised area which is in the configuration of what we would have drawn as a house when we were in first grade. It is simply in the shape of a rectangle with a triangle sitting on top. The 3" or 3 1/16" bore is with-in this second mortised area. After looking at several dozen props on the web site where i found this forum, I'm beginning to wonder if this second mortised area is part of the original design or did some one add this later for whatever reason??????
I'm trying to get some with pictures to post, but so far haven't been able to do so.
Any help would be greatly appreciated.

[Dave]

What you're describing is most likely half of a 4 blade combination, but a picture sure would help clarify it further.

[Dave]

Photos emailed to me by the OP are attached.

They do confirm that it is half of a 4 blade combination set, as evidenced by the mortise on the rear of the hub. The front of the hub has been chiseled out, presumably for a clock or other display.

The design is fairly commonly found and is consistent with one of the many props used by the Navy on Liberty engines powereing a variety of flying boats in the late teens and early twenties, then sold off as surplus shortly afterwards.

The condition of this prop, particularly with the alteration of the hub, and the fact that it is really only half of combination structure makes is practically worthless in my opinion. You will see them sell for several hundred dollars on eBay from time to time, but unfortunately I think that is due to lack of knowledge on the part of the buyer.