If they are 120 size negatives they may not be that old. I'm not that certain the original photographer or the copyrite holder could be determined unless research is done. I like to think of images from unknown photographers as documents from history. They might not meet gallery or publication standards without finding out about who or where the materials originated. I've printed some images from older size negatives that are larger than 120s but well under a 4x5 size. You need a large format 4x5 enlarger for those negatives. I don't know what type of reference books are available on this issue, but I wonder if anyone can cite such materials.