I currently shoot an Intrepid 4x5, which can accept the roll film backs made for the Graflok system. I'm toying with the idea of picking up a Graphic 23 (6x9 roll film back). The ones for adapting to 4x5 go for close to $100 on a popular auction site. The ones that fit 2x3 graphic cameras go for as little as $30. Is there any way to buy one for 2x3 and easily DIY fittings to get it to fit a 4x5 graflok back without losing the consistent plane of focus?