I bought a nice looking GG from China a while back. It has the markings for every roll film back format known to man, which is really nice. However, it was designed for a Wista / Toyo, so it needs about 1.5-2mm ground off either side to fit my Graflex. Does anyone have on tips on grinding glass? I was going to use the disc side of a belt sander with the finest size sandpaper I could find and a spray bottle of water.