My question was about the tops of the pivot pins themselves. Yours look like there is something screwed down through the tops of them, which would be unusual and why I posted a pic of the HSN prop (which I have never come across in real life.)
I don't understand your hesitancy to use a folding prop. "More likelihood of failure"? Are you under the impression that folding props are prone to failure?
Yes, the tops of those pivot pins have set screws securing them in place.
The service guy who's doing my prop shaft seal had a look at the prop. He said he hadn't seen one like it before, but it looked like a well made unit. He did question how this prop would propel the boat in reverse, as the reverse spinning profile of the blades is quite flat. He also mentioned a zinc problem, as the end nut on the shaft is the likely location for a zinc (boat's got no zinc whatsoever right now), and that wouldn't work with the folder.
My "strength" hesitance has to do with pics I saw somewhere of a folding prop blade busting off and punching a hole through the hull. That would suck, although I realize such a failure is probably rare.
So ... I'm leaning toward keeping the fixed prop on for several reasons:
1. I don't race this boat, other than the occasional beer can regatta
2. This is a cruising boat for the Puget Sound, where winds are fickle and sailors tend to spend much more time motoring than they'd like to.
3. Right after the boat splashes back in I've got a 2 day cruise with the wife and friends to take her to her new slip (Anacortes). Not the time to discover I made the wrong decision.
4. When vertical, that fixed prop seems to be well shrouded by the keel. I'll mark the shaft and hand turn it from inside if I want to reduce drag.
5. I can always swap props later while the boat is in the water.
Thanks again for the advice everybody.