I've succumbed and have purchased a well-preserved Korona View whole plate camera. I have two immediate questions that I hope a reader might answer. 1. The camera came with only one film holder. I just won an eBay auction (item 14026680856) for three Rittreck (Wista) holders. Will they be compatible with the Korona? 2. I have a 5x7 back from a 5x7 Deardorff. I would like to have it made into a reducing back for the Korona. It should be a fairly simple bit of carpentry, but can anyone recommend a shop for the work? Many thanks in advance for your help.