I had the same problem a couple weeks ago. My 8x10 Korona View is set up for contemporary sheet film holders, however the plate holders I bought off ebay are 1/4 inch too wide, and possibly too long as well. Perhaps one's best option would be to 1) build a second wider back for the camera or 2) sacrifice some film holders and router them out to fit glass plates. I have a feeling I'll be exploring both options soon.