One of my favorite restored steam locomotives is Santa Fe's 4-8-4 #3751. ATSF #3751 is the oldest surviving 4-8-4 in the US. She was restored in 1991 by the San Bernardino Historical Railroad Society. #3751 was used in the 90s and 2000s in excursion services. After inspections and repairs, she is ready for operations. Currently, #3751 is kept at the SBRHS facility in San Bernardino. An ATSF #3751 DLC Pack should include the following, along with #3751: -Excursion Passenger Cars -An ATSF FP45 -An ATSF C40-8W -A BNSF C44-9W -An Amtrak P42DC Genesis -Maybe a few new freight cars for Cajon Pass -All engines should be drivable separately too, which would add some more operations to Cajon Pass. The pack would include Excursion Train scenarios for the Cajon Pass Route. Also, #3751 could be a DLC for a Grand Canyon RR route, along with the GCR's steam and diesel locos and passenger cars.
The loco is actually currently kept in the Amtrak Yard at Redondo Junction. However, the only way I see this ever happening is if the DTG crew even got any references of the loco while they were at the Amtrak yard during their recording trip to LA, not to mention no current audio sources as well since the loco isnt running atm.