I have an image that I believe dates to 1874. It is modestly wavy so I get light streaks when scanned (Epson V500). Some of the image has flaked off at the edges. It has a dark copper-colored back. Can I safely flatten it? I am content to leave in the other defects; just trying to preserve some image. This is a new scanner for me, so any ideas about improving the scan would also be appreciated.