The basic wagon bodies have been glued together now.
One of the distinctive features of the SAR wagons is the pressed panels in the doors which have the big dent on the outside and the bulge on the inside face.
When designing the kits I represented this by casting the inner bumps as small detail pieces to be glued onto the flat back of the wagon sides.
I've found it's best to do this before fixing the sides together so you can make sure they line up with the indentations on the outside and, in the case of the DZ wagon, that they're aligned properly.
Then it's a very quick and simple job to glue the parts in place on the floor / chassis and the shape of the wagon emerges.