I said something about making One-Page Dungeons for GURPS, and I chose to put my lack of money where my mouth is. This is a work in progress and is much bigger than I had first thought, but I still want to put it out there. I have a lack of game stats at this point on purpose, following Mike Mearls's advice to design your dungeons for OD&D first. That way, they are interesting in of themselves, not because the rules make them so. I'll make them for traps, and a few more for monsters.
If anyone has any suggestions or notices something wrong, please, make a comment below. My idea is to make something like Beneath Castle Everglory, but with the hindsight of having seen Dungeon Fantasy over many years. And a bit smaller.