Compare your oil pressure reading between your old and new pressure sending units or install a mechanical oil pressure gauge.
The mechanical oil pressure above is use to test the oil pressure for newly rebuilt motor using the starter to run the oil pump. The gauge range is only 2 bar. In your case, you will need a 5 bar or 75 psi. gauge. Installing the restrictors will definitely raise the oil pressure readings.
BTW, the picture of the Venturi sump screens is an old picture I posted long time ago. The sump screen has no effect on the oil pressure readings because it is installed at the scavenger pump side. The oil pressure sending unit is installed at the pump pressure side and oil delivery coming from the oil tank.
Tony