From what I've been able to piece together from my limited research material, there was a short period about 1890 where a narrow vestibule between cars was used... basically as a transition from open platforms to the full width vestibules used later.

I'm wondering how many of these cars survived.

B&O "Royal Blue Line" 445 is at the B&O museum. Originally built for the Delaware, Lackawanna & Western about 1890, in 1927 it was rebuilt to represent a Royal Blue Line car:

https://x.com/borailmuseum/status/1275036517396865024

Mid-Continent lists Soo Line 920 from 1893:

https://www.midcontinent.org/equipment-roster/wooden-passenger-cars/soo-line-920/

Any others?

Thanks,

Bob