As you know...I added the zipper to my CPH. I decided that facings
were necessary for 2 reasons: to hide the hand stitching on the reverse side, and to give the entire zipper (and the zipping up process) more substance.
Anyhoo, I knit the 2 facings from top to bottom, using st st...and then just applied them to the reverse side of my zipper's ribbing. It was real easy, and I am very happy with the outcome.