This is a great forum.
I have a 40 year old Myers HCM75 two pipe jet pump.
I see on the end of the motor a small hole hor adding oil for the rear bearing.
I also see in the area between the motor and pump(the shaft/coupling section)a plug with a flat blade slot. This plug is threaded and is easily removed and appears to be for oil or grease fitting. I believe it would take a grease fitting.
What is it for?