Nicely done, I’ll echo your thoughts on the small frustrations. I doubt it was just a searay thing but more of a product of the era but I had to do a similar repair in our 290 to the bilge floor between the motors. The PO must have had a wet bilge for a while and searay screwed the bilge pumps directly into the floor without sealant, so the whole thing was rotten.
Easy once I got the right tools (multi tool) and I’m sure glad I did it now that I stand in the ER on rock solid flooring.
Did yours smell? Once I busted it out it was rancid