Yes, they go the ‘right way up’, ie heads at the top. I don’t think they share any other obvious features with the DB engines.
It’s not an SAE50 shaft, it is very slightly smaller, but the number of splines are the same and it would work because the prop is centred between two cones. We would have to manufacture the cones and retaining nut to suit.

Photos here:
http://www.aeroenginescarlisle.org.uk/Home/mikulin-am42

Pete