I agree the cylinder walls and the rings both probably have significant wear contributing partially to the oil consumption, but since it seems to have increased noticeably over just the last few thousand miles and the engine has had some previous sludge problems I thought maybe the rings were also coked.
Do you all think Sea Foam would be a better option? Could the Sea Foam be poured directly into the cylinders? Probably more cleansers. When it warms up, I plan to pull the oil pan off and clean it out and do an oil/filter change, so I could try any cleaner prior to removing the oil pan and doing the oil change.
As far as the engine having the high mileage, it still runs good and I get about 40 MPG gas mileage, the only problem is the oil consumption. I checked the compression on it at around 500K miles and the compression was still 145-155 PSI across the board.