When a slot (such as Fit Door Panels) is set to “Prefer local”, it will not pull from a Supply Stockpile regardless of what the Imports settings are on the Supply Stockpile. The Imports setting on the slot must be set to “Any” to correctly pull from the Supply Stockpile.
Save game with issue: http://s000.tinyupload.com/download.php?file_id=35295722784777290673&t=3529572278477729067325964