There's really not allot you can do in all reality. Discontinued is the end for a normal parts search. IMHO
After that it's really a specialty search. That is where it's no longer profitable for the dealership. This is where people like you and I really enjoy the hunt. Most people just give up or make something work.
You are so right! I will look up anything and give people part numbers and the dealerships phone numbers that have them. I'm guessing I'm one of the few that will go that far. Standard industry answer is that's discontinued good luck. And that is sad!