A while ago someone was trying to find a Beseler 4x5 above the lens filter holder. I had mentioned how I built one for a CB7 -- which is different. The discussion might have been on this board -- but I don't have time to find it. Right now, there is one listed on EBAY:

https://www.ebay.com/itm/Beseler-4x5...0AAOSwW6BaIweJ

I have nothing to do with the auction.