Glancing through the code, it looks like the ways to "find" one include:
- Equipment in End City chests.
- Randomly-generated books, anywhere you can get them. Including villagers (confirming this would be useful).
- Enchanted bows or fishing rods caught from fishing.
Enchanted equipment sold by villagers can't have the treasure enchants, unfortunately. If their books can, I hope Dinnerbone doesn't decide that's a bug.
As for mechanics,
- Mending has weight 2, max level is 1, and the formula for Enchanting/Levels is y = 40x + 50.
- Frost Walker has weight 2, max level is 2, and the formula is y = 10x + 15.
- Also, Depth Strider and Frost Walker are mutually exclusive. Anomie x (talk) 15:56, 14 October 2015 (UTC)