Hi Ally!! First of all welcome to the group!!
About pictures. i understand from all the reading I have done and from info that someone in here that worked in archiving, all pictures are NOT acd free. That is why when we scrap them e should or NEED to use at the least acid free paper and lignon free is better. Epson and Canon printers are supposed to be two of the better brands of inks that are rated for longevity and the least acidic. It is the glossy paper that is used toprint pix on that is not acid free.
Mounting vellum. There is a specific brand of tape from 3M for vellm paer that does work. it is a rather pain to use though and I have never seen it come in adispenser, just a large roll in a package.
Another way besides using brads or eyelets is secure it with like a picture frame border. Put a drop of glue on a couple of the corners to say hold it in place. then take a coordinating or whatever color and make like a picture frame around the piece and glue that down. It would be like a reverse mat. Does this make sense?
I may have a couple sites I can send or tel you about that has ALL KINDS of military paper and stuff. Let me know -'K?
BTW, are you American stationed there with DH or someone in England?
OKC Dave nada for 05