Richard Ritter modified a spring back for my Deardorff Special. He used a Sinar international graflock back so now I can detach the glass and use my Horseman roll film backs and all the Sinar accessories like the Vario Mask, etc. The job was done well and I now have 5 cameras in one; 5x7, 4x5, 6x12, 6x9 and 6x7. I could even put a (gasp!) medium format digital back on it with the right adapter.