Hey Brian, they are the passenger cars that come with the set, plus the add-on vista dome - see the thread below for my pictures and short video.
https://ogrforum.ogaugerr.com/...34#73509797237484634
The MTH Product numbers: (All are stainless plated)
20-20622-1 - E8 Set - this comes with the #83 A E8 and 4 passenger cars
20-20052-3 - E8 A #84
20-20621-3 - E8 B-Unit #86
20-67276 - Vista Dome Car