Will a Toyo 6x7 Roll Film Holder fit on a Canham Wood 4x5 Camera? I am confused as to whether it will slide into the camera back like a sheet film holder, or does it clip on after you take the ground glass off - which means it would not fit on a Canham. I have done the usual search but have found little to clarify this to me - is it a two piece unit that can be used both ways, or is it one unit? Any help would be appreciated.