Here's some pedigree...

The "Olympic" observation car is one of the two built by the Budd Company in 1937 for the Reading Railroad's "Crusader" streamliner that ran between Philadelphia and Jersey City. The Reading sold the entire trainset to Canadian National in the early 1960s, and the cars lasted into Via Rail Canada service. Its sister observation also survives, in the collection at the Railroad Museum of Pennsylvania outside Strasburg.

The "City of Renton" is a former Milwaukee Road Super Dome lounge and its history also includes service as a trackside restaurant in southeast Portland (first as the "Silver Garden", then as the "Warsaw Express".

BTW, the third dome car from the Spirit of Washington consist, a former Santa Fe Pleasure Dome, wound up going to the Mount Hood Railroad in Oregon. It's currently in service on the excursion train there along with a former Santa Fe Big Dome lounge.