Have you spoken to PP? I've found in dealing with American Standard and Kohler for my fixtures/faucets that customer service can be excellent.
I've had both companies sending me replacement bits and pieces for free. In fact, my Kohler shower doors arrived scuffed in one or two spots. One phone call and they authorized a full replacement to be provided.
Oh, and they don't want the old kit back. So now I have two complete Kohler shower door kits - lots of spare parts!