All the 9x12 holder I have that will fit my Orion Werks & Rodenstock, (and scrap Ernemann) cameras will fit both my Patent Etui's.
In a couple of weeks when I'm back in the UK the idea has been to start a swap thread for 9x12 holders to pass on the spares we have that don't fit our own cameras and hopefully get ones that do in return. I'm fairly sure I have one for Søren
Also I'm looking at getting a few 9x12 film sheaths fabricated, they aren't difficult to make, there was some discussion in another thread. It's taken me three years of searching to find some sheaths, I only need 6 maybe a dozen more.