rawpixel started archiving and digitally enhanced images from the public domain since 2017. So far, over 50 public domain projects were archived and/or digitally enhanced.
Recap of some of the projects
Projects currently on wiki commons:
Pomona Italiana by Giorgio Gallesio
Shirley Hibberd's New and Rare Beautiful-Leaved Plants
The Fruit Grower's Guide by John Wright with illustrations by Miss May Rivers