SRen,
According to the B&O Modeler Nov/Dec 2005 issue, the Sentinel Service paint scheme was implemented from 1947 to 1958. Some of the cars were not repainted until sometime in the mid 1960's. For more information checkout the following:
http://borhs.org/ModelerMag/BO_Modeler_3_2005_NovDec.pdf
http://www.borhs.org
Carl in Florida - - - - - - - - - - We need an HO Amtrak SDP40F and GE U36B oh wait- We GOT THEM!