I would like to give you a hand and be as much help as I can. I have a 12 inch PowerBook G4 that I suspect is afflicted by bug #714345. My sound worked properly under Wheezy. The Wheezy installer added snd-powermac to my /etc/modules automatically. Manually adding snd-powermac to /etc/modules under Jessie does not yield sound. I have never patched or compiled a kernel before but am willing to learn and give it try.
Thank you for your time!