I pulled out some of my chimney from 1929. In the center it was the rounded rectangular clay pipe, stacked up. Surrounded by bricks which supported the clay pipe and had air gaps on both sides like you are showing. This was an old chimney that used to go to the boiler in the basement - not a fireplace.
Somebody has to make the call. There was this dinosaur book for kids in a little free library. It didn’t even have an author or publisher, because it was AI garbage. Full of misspellings, etc. I contemplated throwing it in the trash because I don’t think it should exist. But for some reason I had trouble deciding that for others.
Digitize and delete? Scan straight to OCR and dump the books. One hard drive can store a lot of books.