Proportioning Valve Installation

I suspect that the previous owner of my car installed the proportioning valve incorrectly.  Manual Brakes, Disc front drum rear, Mustang II PV.  Does anyone know what would happen if the brake lines were installed in there wrong places.  It looks like the front input and right front are transposed.  Also, it looks like they installed the input into the output holes and visa versa. The car locks the right rear if I stomp on them, but after a couple stompings, everything seems OK, no lockup.  Front brakes dont seem to be braking as much as they should.  Anyone have any ideas, any help would be appreciated.  The following is a link to a picture of how it is currently installed:

http://www.freeimagehosting.net/1ndl1