>There seems to be quite a well developed science around the use of old photos No doubt. There's a term of art of recovering images of newly discovered comets

>There seems to be quite a well developed science around the use of old photos No doubt. There's a term of art of recovering images of newly discovered comets from old photographic plates, Precovery https://en.wikipedia.org/wiki/Precovery https://en.wikipedia.org/wiki/Precovery