Data Processing Numbers

Baltimore:
Found as IDENT number on BODY & CHASSIS BROADCAST COPY sheets. See some Baltimore examples here.

Fremont:
The first 6-digit number can be found in block #24 of the build sheet.
The second 6-digit number is actually a concatenation of a 2-digit number and a 4-digit number. The first 2 digits are found in block #10 of the build sheet (SCHED NO) and the last 4 digits can be found in block #24 of the build sheet. See some example Fremont build sheets here.

Kansas City:
The 5-digit number following the body date is purported to decode to the xxxth car on the xxx work day of the week such as 05361 would decode to the 536th car on the 1st work day of the week. Whether this is true or not isn't verified.