Odd old shaft coupling on a 70’s Trawler.
It appears as though there is a retention bushing threaded onto the shaft, inside the coupling.
There’s a gap between the outside of the bushing and the coupling.
The bushing is larger than the diameter of the shaft, so will not exit the aft or fore of the coupling.
Shaft tapers down from 1.5” to 1” as seen as the smallest circle in the first picture. Looks to be threaded visually, and the set screw to hold the coupling on was pushing into the bushing so they must have trusted its connection to the shaft.
Coupling is obviously keyed onto the shaft so there’s no spinning them independently without finding a way to grab that bushing/collar..
I’m stumped.
Anyone seen one like this before? Any advice on removal?
Edit: Solved! Brass register is removable, revealing holes for a spanner to remove the “nut”.