To answer your questions, I have a few questions for you to consider. Do you feel that these records would be of value to the general public or your visitors specifically? Processing and accessioning into your collection would be appropriate if they support your institution’s mission and serve your town/county/city. In terms of digitization, if your institution already has an ongoing digitization plan, and you feel the records are valuable, I don’t see a problem digitizing them.
The experts I reached out to suggested that you also consider contacting archivists in your local region for more specific guidance on value of the records, etc.