I realize this is an old thread but I will post this for those that find this thread in future. I have several of these plate holders and like them very much. I found it much easier to make a new back for my 8 x 10 camera which would accommodate both the different distance to film plane and the slightly but annoyingly larger external dimension. This wasn't a spring back but one where I used four toggles to hold the plate holder in place. The focussing glass swung outboard as many other older camera designs did.
