Thanks Nick. I do try to keep the stuff on here original and fresh!
That's great news on resonance - you're making fast progress.
The best thing I can say on learning purr is, when I was learning it I'd realize that some mornings I'd wake up and my voice was naturally gravelly. Sometimes when you're sick it's like that, or some mornings you're just groggy. Look for that and pay attention, and once you've got a bead on what it sounds like, do your best to recreate it in your normal speaking voice at will. Once you find it you'll know how to do it.