Scanning the photo will introduce artifacts - meaning pixels that make up the photo is more clearly seen when scanned and enlarged or zoomed in. They appear as block-like structures in this case.
I suggest you take a photograph of the photo and edit it as would normally and submit. I believe that would produce better quality than scanning.
Scanning will enhance those imperfections, make them more visible. There is no difference between classical scanning or photographing your pictures, if both "tools" are equal good in producing quality pictures. Libraries and museums use photographing techniques, but that is mostly because they are less stressing for the digitized originals.
You have, however a second problem with such pictures: The terms do not allow to publish pictures taken by someone else as you.
Except if Adobe opens a section for legacy pictures I do not see much chance for such a picture.