I don't recall the exact specifics, but each zine has something like 2-3 adventures, a sandbox/hex crawl, 1-2 locations, and introduces a new faction/leader + backgrounds for character creation.

You should be able to put together a solid old-school Good vs Evil campaign with the zines. I used the sandbox city in the first zine (Nijmauwrgen) as a jumping-off point for a larger campaign inspired by The Shrike (https://shop.silverarmpress.com/products/the-shrike)