I made up the frame spacers for the n.g. chassis today. These were made 7.5mm wide so the gearbox will just fit in. The overall width of the frames is 8.9mm. Wheels will be set to 10.3mm back to back. I've had to work all the dimensions out myself so it could all be completely wrong...

To compensate the front axle I soldered a piece of brass between the frames for the axle to pivot on, most people use a piece of rod for this. The brass was cut deliberatly to tall so I could file it down until an axle just touched it, to set the ride height. Then the axle holes (no bearings remember) were slotted using a needle file to give the required travel. If this sounds like a bodge, well it probably is. However the locos will only ever see light use, unless I go mad and build a layout...

Anyway, a photo. Narrow gauge chassis on the right.

It might work, it might not. Next job will be fitting the motor and gearbox.

Paul.