Colin the hex plug is the oil non return valve (Ball and spring) It doesn't hurt to clean it out and fit a new 1/4" ball. Give it a sharp tap with a skinny drift to give it a new seat.
The other screw is a blanking plug from the days when they used to be fitted with an oil tell tale plunger....Just ignore it.
The oil pump should turn quite freely but some slight notchyness is acceptable as long as you can overcome it by hand.
