Each business car train, track inspection train, or shipper's special will be made up differently, depending on the reason for the trip, number of riders, whether or not sleepers are needed, etc. The cars vary in heritage, though many of them come from the heritage roads (fallen flags) the make up the BNSF: GN, NP, SP&S, CB&Q, CS, Frisco, ATSF, etc. These two links show some photos of some of the cars, and the names of some of the cars currently in use.
[
www.northeast.railfan.net]
[
www.qstation.org]
--Sasquatch