Thomas,
Here's a picture of mine with NIMH cells in. I checked out the dimentions of the Trackpower 3200's on there site and musured it all and there is room for them how ive done mine. As you can see ive got the B44 slipper and centre CVD's in too - but im using the J-Concepts centre mounts that have been modified to sit the bearing housings for the B44 slipper shafts.
I run it with NIMH cells in and held the Cell's in using BJ4WE straps..