With much help from Campdaan who provided the split ring pipe hanger and ceiling plate, I've created a back rest for my doll stand.
More images can be seen in my doll album.
http://www.dollalbum.com/dollgallery/th ... album=1358
I still have to get felt to cover the padded block, but beyond that it's fully functional. I replaced the screws for the pipe hanger with thumb screws for easy turning (hard to see in the pictures but they're there), cut down the 1' threaded rod to about 6", and attached the padding using staple style tacks.
Having used it briefly, there are two issues I have with it. First, there are times when I wish it would just go away. By that I mean that when dressing Paige or removing her from the stand, I need to shift the backrest out of the way. With the device attached the way it is that is no easy task. I'm still thinking that the weight of the doll itself should be able to keep a backrest in place, which could then be easily removed just by shifting the doll. This is something I want to experiment with later.
The second issue is that the backrest shifts the weigh of the doll such that I'm seeing different stresses on the neck hook. It keeps wanting to slide forward until the oak dowel to which it is screwed hits the end cap. I need to readjust the hook, perhaps cutting a longer piece of oak dowel for a tighter fit or screw the hook further into the wood so that i has no wiggle room. That's a minor issue and fixable issue, though.
That's about it. It works pretty well otherwise. Many thanks to Campdaan for his design and his contribution to the effort.