Regarding Postal Car #22:
I have different thoughts about the source of Postal Car #22. This comes from my reading and interpretation of accounting information and notes in office copies of ICC reports now in the collection of California State Railroad Museum.
I think #22 came from a baggage-coach combine (#4) that was built in the company shops in 1891 and then rebuilt into a baggage-postal car during the first half of 1892. Later it was renumbered 22 during a later renumbering of passenger cars.
Brian Norden