As said: If you build it according to the description, it will not be able to run on a track. I.e. when build according to the instructions the car cannot run on a layout. You might be able to push it back and forth on piece of straight track (like the display track included with the kit), but it might derail even then. It is meant to be a static display item.
The trucks/bogies cannot swing at all, they touch the frame. So I removed material from the frame and I added brass plates such that the truck can glide on this when going through a curve.
The wheels are not isolated. I did not change the wheels since I can run this car with a live steam locomotive; but it will not be possible to run it with one of my 2-rail electric locomotives.
According to the instructions the axle boxes have to be glued in the trucks. Of course this does not work, some springing and play is needed. So I added small springs to the axle boxes; further the fit of the axle boxes in the truckframe was very sloppy (you should glue them anyway), so I added shims to the axle boxes.
In general in gauge 1 the screw couplers and the buffers also have some springing; the buffers and couplers of this car do have very nicely detailed non-working springing between the frame (see picture). I decided to leave it like that and have this car at the end of the train.
Regards
Fred