They're the ones Amtrak received in 1971 and converted to HEP in the late 70s and early 80s. From left to right its ex-PC née NYC 24/8 Slumbercoach, ex-ATSF 10/6 Sleeper, and ex-NP Diner. The diner is actually still in service, at least until the Viewliner IIs come in large numbers, as Amtrak 8505.