I have read postings on several large format sites. There seems to be no consensus on whether holders from different manufacturers are interchangeable. On one post, Sandy said 2 versions of 7x17 holders are made. 1st version is based on Korona holders and made with Cherry, and the 2nd version is made to Canham standard with Walnut. On a different post, someone mentioned that AWB and Lotus holders are almost identical in specification. On yet another post, someone mentioned that most of the newly manufactured holders are based on Korona holders. Based on the last comment, could one assume that the S&S, AWB and Lotus holders are interchangeable? However, I could not find any definitive conclusion. So if I have a 7x17 camera that works with Korona holders, what new holders could I use on the same camera? Are the S&S, AWB, and Lotus holders interchangeable? Thanks. Jason.