As best I can tell from the examples I’ve seen-
The Cub & Mate had a silver metal cap.
The Johnson Models MS & MD had a red metal cap.
The Sea King Midget had a brown or black plastic cap.
As far a size & thread, they are the same and
more than likely some were interchanged.
Tubs.
A "Boathouse Repair" is one thats done without having tools or the skills to do it properly.
