The rails are there, I do have a couple of pressure plate and springy bits from 2 35mm cameras that I was going to use but in my cleverness to put a hidden sliding counter hole I overlooked the problem that it gets in the way of one of the plates. I have about 6mm to play with depth wise and most likely go back to the foam strip idea (which work well last time), or I toyed with the idea of hinging the plate to the film box which you flip out of the way when loading film and just having a couple of spring epoxyed to the back to provide some light pressure when the lid was closed. One of the big problems is making sure the pressure plate is reliable in seating between the rails when you close the back up.