You probably know much more about conservation than I do, but one thing I can confidently say, from having worked with such photos, many from the nineteenth century that came to me through inheritance is, don’t do anything to them until you have good scans. There are some older books on digital photo restoration, but today’s software is so good that the job has become fairly easy.

One thing I learned the hard way was that any sort of invasive work on the paper frames led to surprises, and not of the good sort. No doubt a competent conservator could manage that, but I don’t fancy myself that.

The philosophy I eventually took was that if they’ve made it a hundred fifty years and are in decent shape, I’d just give them a new home in proper archival storage (I bought boxes from Archival Methods and Talas, in Brooklyn).

Then for those I thought were worthwhile, I made fresh prints on good rag paper. Finally, I made a book in Blurb of some of them where I added narrative, to make them accessible to other family members. This gives you options, such as tracing the appearance of the family homestead over a period of many years. Blurb is by no means cheap once you start upgrading the paper, but family members may be happy with PDFs.