Seeing how it's my thread, I can ask what I want. :D
I guess that was very "charitable" of Mercury to remove them from the US and let them remain overseas? Would you opt for that outdrive, were it available here, over a Bravo 1?
So the Mirage prop show has a solid hub?
On the engine pic I see too many hoses on the exhaust risers. Did it preheat the water for the engine or perhaps closed cooling and the heat exchanger is not in view?

Oh dude...that outdrive was SO smooth. The shifting was the smoothest you can imagine, basically hydrostatic. No clunk, no 'dog clutches'...just a...surge forwards or backwards, like velvet, with a nice little whine. Throw in there's a tilt switch on the gimbal ring that made working on it so nice. Yeah, solid hub like the one shown in the pic below.
https://cimg6.ibsrv.net/gimg/www.off...f210e714a0.jpg

https://cimg6.ibsrv.net/gimg/www.off...a0529eebcd.jpg

The solid hub Mirage props were also used on Mercruiser TRS outdrives.

Keep using the Delrin aka plastic hubs until you have repeated failure issues. I'm about 430hp and have had no issues.
They may save your prop and/or outdrive if you hit something.