DSP&P 2-6-6 Mason-Bogie

In the book "Recent Locomotives of 1886" published by the Railroad Gazette there is a nice drawing (engine is marked for DSP&P) and a short mechanical description of the 2-6-6. In the preceding pages are more technical descriptions and elevation drawings for a similar Mason 0-4-4 (also 3' gauge) including detail of the steam joints.
Robert Ulin in Colorado has produced a 2.5" to the foot scale model of this engine, thus has created his own set of drawings for the engine.
Does anyone know of another source of reliable information on this engine? Or maybe her predecessor 0-6-6 that ran on the North Pacific Coast? Drawings from model magazines are not acceptable. I've been led down the wrong path by these before, and I don't trust them anymore for engines (cars & structures are better.) However, drawings made by scale model companies for a product are usually within the ballpark. Are there any original blueprints for these engines around?
I've decided to start gathering information on both the NPC 0-6-6 and the DSP&P 2-6-6 for possible future use in live steam model building (5" scale, 15" gauge), and the eternally wishful replica building (hey! One can dream..can't he?)
Any help y'all can give would be highly appreciated! :-D
Cheers,
Curtis F.