Concerning the metal cap that has been mentioned at the front bearing. If we are talking about the cover bolted at the inside of the front knuckle, I think you may be speaking of just a dirt and water shield to protect the otherwise exposed bearing. It has no connection to the bearing other than to protect it. And yes, the same bolts that fasten the bearing to the knuckle also fasten the shield. The bearing itself doesn't have a shield that is anything different found on the rear. Here is a pic of the dust shield found at the back of the knuckle.
From everything you fellas have dug up, I wouldn't have any reservations on trying the rear bearing on the front. The shield would merely be reused with the new bearing.
I had removed all four of my bearings to add longer wheel studs. I have pictures somewhere.