Ohio Falls Trucks *PIC*

There is a pair of trucks under a Sumpter Valley stockcar on display in Prairie City, and I'm trying to find out the history behind them. Most likely the trucks were purchased by the Sumpter Valley Railway from the Utah & Northern, but we aren't exactly sure what type of car carried them. I'm investiagting the possibilty of them coming from one of the U&N insulated boxcars, but I don't have a good picture of one handy. There is an excellent photo of Sumpter Valley boxcar number 2, formerly a U&N insulated, in the Colorado Rail Annual Number 15 if anyone has a copy to do a comparison. The trucks seem rather unique, even by SVRy standards, as most of the freight equipment rode on a style more similiar to what was used on the DSP&P, which I'm told was a standard Union Pacific design used by many of the narrow gauges under their control. Anyway, if anyone has any ideas about the origins and such of the trucks, I'd love to hear them.
Thanks in Advance, Taylor