Illinois Railway Museum. Their roster indicates it is an Alco RS-11 that was built in 1958 and arrived in 1983. It runs on AAR-B trucks with GE 752 traction motors and is powered by a 12-251B engine rated at 1800 horsepower.
A Flickr photo with four engines and at least 3 liveries.
Marty Bernard processed and posted five Roger Puta slides of the TP&W.
|1. TP&W Alco RS3 207 making a transfer run from its Peoria, Illinois yards west on NKP trackage in June 1963.|
|2. TP&W Caboose 504 at IC Crossing at Gilman, IL on July 22, 1962.|
|3. TP&W General Office Building at main yards and shops at Peoria, IL in June 1963.|
|4. TP&W GP30 700 and GP35 902 in Logansport, IN on November 25, 1966.|
|5. TP&W GP30 700 and GP35 902 in Logansport, IN on November 25, 1966.|
|Howard Keil posted|
[If you follow the link and access the comments, you will see three more engine photos.]
A Flickr photo of 2056 doing work.