Also blackpowder that couldn't be used as a weopon but instead to destroy a house or search for resources by blowing off bits of a mountaian or better yet fireworks. Black powder is made from soft wood charcoal (just use burnt wood) sulfar and potasium nitrate (a naturaly occuring mineral)
While in a mountain you should be able to search for undiscoverd veins of mineral by using a pickaxe.
These new found veins should remain unammed until someone puts it up to what the mineral or a object that directly usses the mineral (like an iron longsword but not a car because a car is to complex) is or tests it in some mannor.
Also add fire as a weopon. Make a weopen fire pit that could have a lock on it. Only certain weopons could have have fire used on them to make them more deadly. For example metal melee weopons could be made red hot to deal a more devasting blow but increase the deteriation rate. For wooden weopons the would deal a lot more damage but would deteriat to ash with no way to repair them in 1 cantr hour
crowbar doubling as weopons
a way to bind lots of notes into a book
aqueducts as buildings or some other way of transporting water to places that don't have it
An easy way for new lands to com in contact with the old lands are small wooden boxes that can hold notes and 1 gram of most resources. These boxes would then be put out to sea and float away too a distant land were the people of that land could learn about new reosurces and cultures.
A type of dieses that didn't damage you but instead made you work at a lessend rate. For example if you could harvest 200 grams of corn a day completly healthy with the diesese you could only harvest 175 grams of corn. Also each few days you have the diesiesa its effects get worst.
If the diesese is found on a land with a abundance of grapes and mushrooms a mixture of grapes and mushrooms would provide a temporary relief but to get the diesiesed removed you would have to get herbs from a distant land.
This would work both ways with new lands and old lands because if there is a food or herb resource the old lands have it could be the way of curing the dieses.
If you've reade this whole thing ill give you a cookie!!! 
