Tim, I'll make a suggestion based on my own past experiences with Gibellini; you're free to take it or ignore it. This really only applies if you're in North America.
Get in touch with Richard Ritter in Vermont, and send him your camera when he will be available to work on it.
I've no direct experience with him, but he makes his own cameras and is well-versed in the use of various woods and metals.
If you find a Toyo holder, even as a loaner, send it to Richard so he can take care of that problem at the same time.
It's worth paying Richard the repair money, rather than trying to get a free repair from Gibellini.