The 1/16 inch diameter flow control orfice is at about the level of the input fitting on the side of the filter housing, a couple of inches below the top. If the canister is draining below that level, you've probably got a hole rusted into the standpipe near the bottom. That will also cause a loss of oil flow to the engine if the hole is big enough. Try removing the filter canister, clean it up, and fill it with a lightweight solvent like mineral spirits or Diesel fuel to look for the leak. It should not drain below the level of the flow control hole.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!