This character is only just quite not there, the only problem being that Master Rillcreek's advanced age does not come through in the slightest. I would caution against trying to play his age to the hilt, as you have wisely steered clear of, but only too far. Consider tensing you abdomen and hollowing out your mouth, speaking more from the top of the throat then the front of the mouth. But it should be remembered that Master Rillcreek is quite vivacious for his age, and that these things should be done subtly, as one's tendency isn't to do.

... but it's with relief.:) I'm always picked for old characters because of my precise enunciation. It's a pleasure to hear I don't sound old, even if it's not from the person doing the casting.:)

That said, I'll keep the tips in mind... but remember, the director has the final say.

Seems pretty close... however, if you can't get it quite right with vocalizing alone, there's always computer modulation. Easy to get higher-pitched and maybe tweak the vocals a bit.