I recently got my hands on a polaroid back for the Mamiya 7. Its in really good shape, especially the glass/fiberoptic panel. The one thing Im concerned about is that the panel seems to have wiggle room, it shifts side to side and up/down a small amount, but my bigger concern is it moves in and out. When i tried to google to see if anyone else had this problem I kept reading that the panel is a "free-floating" glass panel, and this is where I got really confused. So I guess what Im asking is if anyone knows if this is normal, that the panel moves in and out.