uintah rwy railcar number 50

I was wondering if anyone has details on the Mack Uintah railcar that could help a 3d modeller to make a more accurate model. We have the drawing that is doing the rounds, but there are some omissions . At the moment the bogies are lacking in detail as you can see in the screenshots of the car in game at Watson . The modeller ( who is 90 years old BTW and has been making models for about 20 years ) wants to know whether the front bogie pivoted or not, I know from Rodger Polleys book the rear axle was powered but how ? was it a chain drive like the later Buick and model T railcar, or what ? any help would be greatly appreciated. If we can find more info on the railcars he will have a go at making the Model T as well.