A)
Lincoln-only dealer, and B)
BG shop most likely options. Dealer, you may have to talk directly to the trans tech for results.
These guys might be who you need:
Honest 1 Auto Care - Marietta
Distance: 9 miles
1391 East Cobb Drive
Marietta GA USA 30068
Telephone: (770) 635-2487
Just tell them to do a 3x drain/fill of the PTU with short "exercises" in between (any gear but P and N), if there's no drain plug available. Show them a copy of the HOWTO if you need to.