[Jac Mac]

Originally Posted by Gaz64

This doesn't make sense. Where is the scavenged oil going and what are we doing with it?

Normally, the scavenged oil goes to a swirlpot collection tank and the engine pressure pump draws from that tank.

Only because your thought process is clouded by the image of modern practice, the scavenged oil goes to the swirlpot/external tank, from the bottom of that tank via a line back thru that 'hole in the triangular pad' & onto the pickup tube of the original internal pressure pump of the engine, system is then on thru the pressure system as per normal.
Does not get rid of any of todays associated problems like oil pump drive-dizzy gears etc, but then when you think about it with a nice continous supply of de-aerated oil from the tank life might have been easier on the pump drive, and maybe the oils were slightly better back then along with real mechanics rather than just the parts fitters of today.