This thread is as much a commentary on modern US society as on photography. It's sad that fear of being sued seems to be the main decision factor involved. Questions like: "Do these photos have historical interest?" or "Is there a business case for this?" seem secondary to "Will someone sue?"
My instinctive answer is that if you honestly believe these to be out of copyright and you think there's a business case (i.e. a market with sufficient demand for you to make a reasonable profit) for what you propose then go and do it. Obviously both of these require a little research.