This may be too massive an undertaking to consider even, but there's Ketaros Treasures with its respective patch that moves a few otherwise unobtainable items, if you're looking for something to do! I'd definitely use that liberally to find the dozens of postcards, magazines, and boardgames it adds as collectibles. :) Thanks for even opening this to suggestions, regardless of if you choose to undertake this.
Further Collectors Guides (2 comments)
Obviously, the mod must add a collectable of some form, be it magazines, bobbles or something else entirely.