As for orifice restriction original 40's and 50's bypass filters the restriction was in the return tube that the filter mounted on, not the inlet.
For example, the Ford L134 motor used in the GPW had a .064in orifice as shown
IN THIS PHOTO to regulate oil flow.
Putting the restriction AFTER the filter evens out the flow through the filter.. it more or less sees the same flow through the filters life. Putting the restriction BEFORE it means that the flow through the filter is variable.
For screw on tpe filters this may not hold true.. but for cartridge elements is does.
