Edited:
There is no match because I see splines no a keywsy. Back in the day components like these were similar or the same construction, no matter if it was for turning a fan, pump, or tire, some manufacturing company could have held the patent, or it could be that it was the most efficient method to transfer power at the time (same as today).
Okay now it looks like like there's a spring ring (the baby blue tack, it prevents bolts and nuts from backing off or out), that goes around the part, (the blue tack shows this ring going around what looks like a hex head bolt tacked red). Then I've tacked the 2 main parts green and yellow.