I've just scaled it down do be 36 mm wide to fit the HO scale from the original model:
Removed some internal parts from the body to be able to fit an electric motor. The floor is also re-designed to fit stock chassis.
Placed a pantograph insulator on the roof and ordered a stock pantograph from aliexpress.com. The metal bars are made of paper clips.
The knuckle couplings are also from the market.
More details at http://www.3dprintrc.com