The most important thing is to preserve the IMAGE. Of course, I know there's value in the original prints but if they're somehow destroyed... you have nothing left to see.
Unless they're kept in a safe cool area, free of humidity and heat, or temperature controlled... well, I think you get the point.
But, even taking them out once every few years, you have no control over the type of paper they were printed on... acidic based, not the modern acid-free archival paper we have today (also used in good usually expensive). Besides, if someone used aerosol sprays or spray cleaners... that would linger in the air and potentially affect, however minimal, the mages and promote fading, however minimal.
Your only potential problem in scanning those vintage imagines is in the handling. But, surely you'd want to preserve the IMAGES to share with family, relatives and friends.
IF you have a substantial number of those images, I'd urge you to invest in a good flatbed scanner and digitize the images and later have an experienced person do restoring work to bring out the faded portions, fill in or repair scratches and enhance details. You have some images that are of historical value; care for them and save/secure the images for the next generations.