What is this?

Update: I decided to make sure that my assumption that the car has 4 corner drums was correct. It was not. It's got discs up front and they seem original to the car. Should've checked that a long time ago. That means that the brake unit is a proportioning valve and not a distribution block, as I learned from someone's previous comment.

Another Update: Got the proportioning valve off the car. The model number is KH 89410(Kelsey Hayes). After looking it up, it seems like this piece is used on mopars. Any thoughts on rebuilding this piece and keeping it?