Also interesting is the engine: a product of a small (and to me, unknown) manufacturer. http://en.wikipedia.org/wiki/Brookville_Locomotive_Company
I didn't know about them either. I wonder if my parents rode on one of Brookville's products in the 1920's when they went on a logging railroad inspection trip in a flange-wheel equipped Ford Model-T.....?
Brookville Industrial Railroad Switchers - NE Rails A builder of small industrial engines. Since non-common-carriers are poorly documented, the first time they were brought to my attention (I had heard of them before) was when I learned of the Metro-North DES-70B switchers. And now they build road power too. Oddly attractive engines, and the paint scheme reminds me of CN with reversed colors.
I wonder what they use for the frame and trucks: a construction made bij their own, or retired older engines?
Those trucks look somehow different from stock Blombergs. The fuel tank certainly isn't EMD. Can't tell about the frame. I'll guess they're like GS21Bs: trade-in trucks, but new frame.