I picked up a GA645 recently from the APUG board. I'm thrilled with the condition and I think I got a good deal. I've shot one roll through the camera, with results which are very nice IMO. However, when loading my second roll, I noticed a few specks of black gunk on the backing paper, and I realized the light seal at the hinge was a bit sticky, and seemed somewhat degraded. I'm comfortable camera's light-tight at the moment, but it may not be for long! This seems like an easy job, but I have no idea what material to use, or where to get it. Can someone help? Thanks!