We would like to digitize newspapers that were published prior to 1923. Since the paper is still in business, does public domain apply in this case? They are very difficult to deal with. We do have a contact there. However, if there is nothing stopping us from digitizing the older issues, we prefer not to deal with them. Would this also apply to other newspapers who are still publishing today but whose content does exist prior to 1923.
You have confirmed that the “Buffalo Evening News” (and other iterations) content originates BEFORE the strategic “1923” date confirmed by the Copyright Office (Circular 15a) as in the public domain. This is true whether the original article or image was owned by the paper, or licensed by the paper and owned by another person or entity.
Once an item is in the public domain, there are numerous ways for either the original owner, or another, to create a copyright in a new medium re-presenting the content (this is a motivating factor in many “special editions”), but the original is no longer protected, and may be digitized as you describe, without concern about an successful infringement claim.
One caveat on the “Buffalo News” content: there could be a concern as you promote the newly created resource. “The Buffalo News” is a trademark owned by (interestingly) The Columbia Insurance Co. (registration # 75834888). So while you can list the resource, I advise against using the name “The Buffalo News” in any promotion of the collection. That is for optimal safety and so you don’t get a cease-and-desist.
The good news is that the “Buffalo Evening News” trademark is officially “dead” (see attached screenshot). This may be used to promote the service, should you wish to do so.
This analysis and a similar caveat would apply to any other newspaper.