Through considerable luck and diligence in shopping eBay, I picked up a total of 15 usable plate holders (726/6) that fit my Ziess-Icon and Ica Ideal 9x12 cm cameras some time back; with film sheaths enough to load them all, and 9x12 cm still available in limited emulsions, I can make a nice expedition with my 80 year old cameras. Overall, I've been pretty happy with them, but there are a couple with obvious large gaps in the dark slide velvet that causes them to leak light.

Replacing velvet is said to be easy, if you can get to it; unfortunately, these holders appear to be either soldered or crimped closed (unlike the plate holders for many plate cameras, these use a geometric light trap around the frame opening, no velvet at all on the camera, and thus have an enclosed, double-velvet dark slide slot). Has anyone seen any way to get the velvet out and replacement material in on this type of holder?