Your measurements sound good to me. Gears are worn in now. If something needed to be tightened up a little it would likely make the whine louder. I’ve have, and have had, a fair amount of 20’s & 30’s motors and I’m able to leave a motor on for weeks at a time. As the grease is replaced with water, the whine gets louder. I can tell when its time to be adding more grease. This is normal for this motor and its 30 years newer. Video Link – https://youtu.be/N-Hsh57stUw
A "Boathouse Repair" is one thats done without having tools or the skills to do it properly.