To answer the reply-the strap was centered on the sail drive such that the release pin was touching the casting. The weight was carried on the castings, not on the prop/shaft. The straps were touching the hull on both sides, but it was obvious the strap did not follow the hull.
I temporarily rigged up a water feed and ran the engine. With a helper, we put the sail drive in forward and reverse at idle, then stepped up the rpm
to full throttle. No nasty noise
on the outside or inside next to the sail drive. Visually inspected the penetration. No apparent damage to seals
and fasteners. Thanks for advice everyone.
If the worst that comes of this is a bent prop I am impressed. Actually, the edge on one blade has a ding from the release pin.