The third crafting item requires:
Sawmills
Skunkupines (they spawn from the targets).
If this follows other events, you will need 22 drops from the sawmills and 44 skunkupines. If you don't park a monster, you should get all your skunkupines from targets.
Also, the first item does not require anything from the event building. It was just part of goal 2. Sorry for the misinformation