I've a similar situation, just received my great great grandmother's bible (published in 1890) from my dad's cousin and I'm looking to preserve it as best I can within reason. I was going to go the route of acid free box but the dimensions of the book leave me scratching my head; do they make boxes for books this large? The book measures 4.5 to 5 inches thick and is rather large with metal clasps. See attached photos.
What would be some ways I could keep this monster safe?