Pile Driver OB is currently undergoing restoration by the Friends of the C&TS in Colorado Springs.
I wrote the history of Pile Driver OB that appeared in the Prospector magazine, Volume 3, issue 1. You can purchase back issues of the magazine at:
[www.drgw.org]
OB was also covered in a book that I wrote: RRobb Volume 7 which covered D&RGW work equipment OA-OZ.
I also wrote an article on the restoration of OB that was in the Green Light newsletter of the Rio Grande Modeling & Historical Society.
Hope these resources answer your questions about OB.