It would not let me import the single drive while it was in a foreign state.
Then something is broken. That should have been your ONLY course of action. All others will yield corrupt data, with the "possible" exception of forcing online the amber/failed disk.
Import if the array is offline. Clear if the array is online.
I'm going to try and flash the firmware and see if that makes a difference with the one drive listed as amber.
This will not magically make the missing/failed drive online. In most cases, updating firmware when the array is in distress is dangerous and a bad idea.