I also tend to say not to dismantle the album just because the pages may be acidic, unless there is a good reason to do it. If it is in a good shape now, there is no reason to think it will deteriorate more, being kept in stable conditions. From what I’ve seen, these kind of albums had the photos very well glued to them, so it is very difficult to separate them from the album without risking them. You shouldn’t try to put humidity to relax the glue, because the humidity may harm the picture itself, as said in another comment. And of course, as you said from the beginning, it’s not only the photos, it’s also the album as a whole that has an historical value. I guess the pictures don’ t overlap completely one on the other, so it could be digitized as it is?