I've been on N474DA twice. First it was on 11/10/85 from ATL to DCA. The second time was on 3/16/96 after it had become a Delta Shuttle aircraft. I flew on it from LGA to DCA.
I didn't know any Delta Shuttle aircraft had been removed from service, except their original ones with the PeoplExpress registrations that they inherited from the Pan Am Shuttle.
Fly Eastern's Golden Falcon DC-7B