I ADDED ANOTHER HORN. The Proto 2000 SD60 model with item number23501 (Chicago & North Western #8034) was part of the second release of the SD60 and was likely released around 2002-2003.
Item Tag: 2 1/8"
This item is aProto 2000 HO Gauge 1:87 Scale WM Western Maryland EMD GP-9 II Diesel Locomotive, 23713, in the original box with instructions, warranty info, and bag of screws and detail parts for installation.