A couple of like-themed watercolors came in with similar issues. Dirt particulates across the surface of the font, and on the back acidic tape and adhesive had transferred acidic compounds to the paper which led to staining. As far as the watercolor paint, both came in with compromised portions. These parts were in-painted to return them to their original state. We prepare some before-and-after to highlight how dramatic this effect can be even for a watercolor.
The watercolor with the two fishing shanties is by Nathaniel Steinberg (1893 – 1976) and the watercolor with the dredge is by an unknown artist. We restored another Steinberg watercolor back in 2017 and you can that blog here.