Wellcar Stackcar Container railcar train HO 53 ft

Wellcar Stackcar Container railcar train HO 53 ft. Issues with a bit too narrow bay (need to Dremel about 1mm each side), no connection point on common bogies yet (work in progress). Maybe someone can improve on it since my skills are weak. I was very fortunate to have a talented friend help me to get it to this stage.
There are three distinct different wagons as needed in a A-C-B stack train arrangement with 2 common bogies. You can use the 100 ton HO bogies published here on Thingiverse wi