WOW, thats ALOT of oil usage, sounds like you might have scored piston walls.
Not to be discounted on these cars is a malfunction of the oil separator system in the air cleaner. (Including the baffle of recent discussion, the hoses, etc.) I own the Chicken Wagon because the PO thought the engine was toast. Five minutes with a screwdriver and that dog was converted to something we drove a couple of hundred miles home. Not that we knew anything about it at the time, we just thought that having the breather hose mostly occluded by a clot of rubber snot couldn't be doing it any good. No, it wasn't! The oil reclamation system in the crankcase ventilator depends upon relative pressures being right. The oil in the blowby in this case was pooling and slopping over into the turbo intake. Big oil consumption, bad intermittent engine noises, and a lot of carboning up. All gone after fixing the breather hose. -- Jim