Copyright is convoluted, yes, but in for things published in the era that Maxwell's drawings were created (basically anything before 1978), there were formalities that needed to be adhered to in order to maintain copyright protection. Cornell University maintains
a very helpful guide to copyright term on their website. The quick summary as it applies to John's drawings...
Anything John created and sold copies of would fall in the category of "published works".
Anything published before 1978 that has no copyright notice is now public domain due to failure to comply with formalities.
Anything published 1923-1963 with notice and whose copyright registration with USPTO was *not* kept current is now public domain.
Anything published 1923-1963 with notice and whose copyright registration with USPTO was kept current is in copyright protection until 95 years after publication.
Anything published 1964-1977 with notice is protected until 95 years after publication.
So, I believe the key questions here are:
- Of John's original works, when were they published? (Because 1963/1964 is a critical boundary, this is important)
- Were they marked with the correct copyright notice? (Not the ones I have)
- If they were and it was before 1964, were they registered and was that registration maintained? (Very unlikely, but hard to verify)
As for unpublished stuff, it's a bit different...
Unpublished stuff with a personal author is author's date of death + 70 years.
Unpublished stuff with a corporate author is 120 years from creation.
The ones that were essentially direct copies of railroad plans are probably a bit of a stickier issue. They were published, but I don't know if that was with railroad permission or not. If he had explicit permission, then I believe they'd be considered a published work and fall in the above rules. If not, then they were possibly an infringement themselves and thus probably don't count as "publication" by the author (the D&RGW), and therefore may fall under "unpublished work of a corporate author".
That said, I really, really doubt UP cares about such incredibly old historic paper with no relevance to their current world. At least they've never given me trouble about it, and I've actually had a few requests from them for copies of things I have that they don't...
All of the above is my understanding of the law, having tried to educate myself in it as it relates to many of the artifacts I deal with. I'm an engineer, though, which is pretty much the natural arch-enemy of the lawyer and therefore I may have misinterpreted something.
Also, even if you're right, defending that against a better-funded opponent in court can be prohibitively expensive.
