Breckenridge Locomotive *LINK* *PIC*

I am trying to track down the details (builders number, Baldwin Class number, History of use, and various dates) for the locomotive now known as 111 on display at Breckenridge Colorado.
This is the loco that was formerly at the Sundown and Southern, purchased by the City of Breckenridge, and that the Colorado Historical Society is proposing to lease, restore to operating condition and operate at the loop.
The Society’s proposed contract includes a requirement that the loco be listed on the National register. While I don't think this is possible, the information would help in understanding the situation.
Thanks
Randy Hees
P.S. the car in the photo is now restored and operating