I really don't mind using 4 x 5 film, I cover almost the whole negative but the camera does look a bit weird. I also realized that I could probably add the plush strip and some kind of stop, and just put in some 9 x 12 sheaths.
The link in Poland for those sheaths looks interesting--I have a couple of holders that fit in the Bergheil (or I can make them fit if I shim the thickness to 4 mm). The camera that takes the 9 x 14 plate holder had an Agfa roll film spool in it, and I did manage to slide off the back plate and it looks like the plate holders (which are marked 'ICA Akt Ges Dresden' and '721/8') would slide in if I cleaned out some corrosion, but there is no ground glass for focusing, I haven't figured out how to get out the pressure plate for the roll film, and the lens doesn't lock into place when it is pulled out. Haven't figured out the shutter, either, and the lens (just marked 'Ensign') is pretty slow (first 4 stop marked is 7.7). I only bought this lot for the plate holders, but I guess that happens. I have another 9 x 12 with no brand name (also came with the hunt for plate holders) and the only problem with it is that the Compur shutter on that doesn't work.
I'm taking this easy right now, since I was already set up for 4 x5, it is almost easier with that size though shooting 9 x 12 is a long term plan.