Pro tip: let the old guy at the estate sale show you how he opens a stuck book
I was at an estate sale in Baltimore about 4 months ago, digging through a box of musty old hardcovers, when this older gentleman next to me noticed I was forcing a 1920s cloth binding open to see the title page. He put his hand on my wrist real gentle and said, "You keep doing that and you'll crack the hinge before you even get it home." Then he showed me how to hold the boards flat on the table and just barely lift the cover, working it open from the middle of the text block instead of the spine. He said he'd been a library mender for 30 years and had seen way too many books ruined by people in a hurry. I tried it on the spot and the book opened like it was brand new, no creaking at all. I still do it his way every single time now. Anybody else pick up a trick like that from a total stranger at a sale or a yard sale?