T&NO B-50-25 series 54850-55199 had wide seam doors, but
T&NO series 55200-55699 had Superior doors.

As everyone here should know, any box car built for a US railroad
from 1944 onwards had steel running boards (until after the era of
STMFC interest).

The first use of the diagonal panel roof was 1948. Since these cars
were built 1946-1947, you know that IM has made a mistake if they used
an RP roof.

Ed Hawkins noted the first use of the diagonal panel roof was on
a series of GN 10' 12 panel box cars -- just like the IM kit!

Tim O'Connor