Turns out the part wasn't "in-country" after all and has to come from Germany AGAIN. In any event, I got some clarification on what they'd found. The wheel-locking was unrelated to the leaking seal behind the clutch (although that was clearly a problem). The rear wheel BEARING (which, I was assured, is NOT considered a "wearable item") was failing and THAT was what was causing the wheel locking.
So now I wait for that part. And then the dealership turns in all the information to BMWNA and they decide if everything is covered or not...
Updates as I get them...