Parashooter,
You are right they are a slip fit not pressed in. Mine looks nothing like the photo. Mine is .405 x .502 inches, the dovetail in the barrel is almost twice as deep as a sight dovetail at 1/8. Also mine is not reduced in size as the photo, same size all the way to the end. If anyone wants to try this the threads in mine are #12 fine thread.
It has been 40 years since I took mine apart when I put the scope on it. The electrical friction tape repair was done before I got it and maybe before my mother got it also. Well you gave me an incentive to clean and lube it. Thanks.
Went back and looked at the parts assembly photo, completely different, on mine the spring goes through a hole in this dovetail stud. That is why my stud looks so much larger than the photo.