Prussian Reserve Infantry

[Chris Pringle]

Are they already not in the public domain and available on-line?

That sounds like copyright myth #4. Just because it's online doesn't mean it should be and doesn't mean you can use it too.
https://www.copyrightservice.co.uk/copyright/copyright_myths

[John Cook]

OK.  Not my specialist subject.  As I said I don't want to be drawn into a discussion on that.