I had converted Ironfang Invasion to Pathfinder 2nd Edition rules, back when Age of Ashes was the only PF2 adventure path published. The crafting rules in PF2 are much slower and demand more raw materials than the PF1 crafting rules. And, of course, the PCs could not simply walk into Phaendar to buy materials after the Ironfang Legion conquered the town. I was worried that they would have trouble crafting arrows. That worry was wrong, because they looted plenty of arrows off of dead Ironfang patrols. Nevertheless, I invented a system for gaining raw materials for the forest. That might have the flavor you need.
Basically, they hunted in the forest not for food, but for plants and minerals that made good raw materials. I used Survival for the skill check and the DC was fairly easy because Fangwood Forest feels very lush. That will make the crafting feel more natural.
As for using an acorn in place of a pearl, acorns are too common. You want a rare plant with mythology behind it, like a four-leaf clover or mistletoe or hawthorn berries. This is a good time to ask the players for suggestions what they would think would feel special. Finding the special plant or mineral would have a higher DC than regular raw materials for magical crafting. "Oh, you rolled a natural 19, which sums up to 25. You did not just find raw materials, you found mistletoe."