Thank you for your feedback!
The ore and leather are mined in the Black Forest, not in the Rats Dungeon. I'll think about how to give the player a hint where the ore is located.
Also, there is a bestiary in the menu, where you can see the loot from monsters and where the monsters are located.
As for saves, I would advise you to save manually more often, auto-save can help if you forget to save, but I would not use it as the main save