These special items are used to craft the ultimate kits, like maximum ammo kit, or max arrow quiver, only weapon holding kit does not require any special stuff. To unlock these kits you must craft the previous ones, like craft all 3 ammo kits, 4th one aka the maximum one is unlocked.
Ok, kits like ammo, arrow quiver etc does not require any recipes, all you need are the skins, now check all the kits to see which animals you need, kill them and craft your loot, then when you get all three for each category the 4th, i.e the ultimate kit is unlocked to be crafted by using special(legendary) animal skins, like man eater shark, black panther etc, when you have those skins you can craft those max kits, and as long as you do not craft the ultimate kits those special skins will remain in your inventory.
Legendary animals can only be found in path of the hunter quests and must be killed with arrows.
PS: If you posses the necessary skins, just double click the item to be crafted, recipes are required only for syringes and special arrows, not for kits.