I'd like to add some thoughts. First off, the insert that is passed around seems to be a hollow metal tube, with brass showing at the tip. It's rusty too.
This is different from the grey, coated and tapered blade that is in the ANH stunt.
That insert is a solid cylinder, the bottom has no hole. Maybe it was drilled and tapped for a threaded rod..
There appear to be two types of blades there. Long, lighter coated ones, and the rusty ones with a thinner bit at the bottom.
Also, I feel that thinner part of the rusty blades had to be a bit long. For
this prop, the bottom half of the Graflex bulb socket was removed, and some kind of insert pushed up against it, and screwed in place
just like the ANH stunt was. Same sort of thing do y'all think? (look in the socket and switch holes)
However this prop makes me think there were no threaded rods, thats a solid one and it runs right through to the insert.