I would definitely try a junk yard if you have one near by. I recently went back to a stock intake as well but bought everything from a junk yard for 10 bucks! However I had to go to 4 different focus's parted out to find everything.
But I want to say the MAF tube screws were T10 torx with very aggressive thread pitch (sorry can't be specific). The airbox you could easily go to a True Value (if you have them) to buy what you need since you already have two of them. But yeah, junk yards. A Focus owners best friend.