Schweitzer Comics offers a very nice paper model Nativity Set. It’s not quite free, but it is “pay a fair price.”
paper model
Free Paper Models: Laboratory or Alchemist Equipment Models for Your RPG!
For furnishing your dungeons, here is a set of models of alchemist / laboratory equipment free for the downloading.
Free Dungeon “Furniture” Downloads
Stock your dungeon with Heroquest style furniture! There’s lots of good stuff here for a wide variety of periods for skirmish battles.