That's cool Tyler, I look forward to seeing the pics. Is your grandmother happy that you cleaned out a closet for her? Check all the mattresses in her house. Quite a few people from that era keep cash in places like that.
My GGF bought all his kids houses for their wedding gifts with cash from the mattress.
EDIT: BTW, I'm not suggesting you take the cash. My wife's grandmother sold her farm after her husband died and remembered years later about a stash of cash she left behind in a home-made wall safe.