Panagioti in the rear wagon we have a small cut at that point above altenator. Roco has cut a longer section in order the model can handle sharp curves.
In the model I made before 12 years (and now it is in Adelardo collection,) I used suitable bogies from a Kleinbahn Austrian bagage wagon which are as the railtop ones. But I cut the extentions which hold the brakes pedals from the outer sides. This was a mistake of me as in the photos I had these part of bogies was invincible. So I didn't have space problem and I decided to add these plastic strips to be closer to original.