One of the advantages of casting carriage sides out of resin is how rigid they are.
The picture shows the eight parts which make up the basic bodyshell of 119 glued together.
Now if these were made from styrene rather than cast the sides would be bowing inwards like two bananas placed side by side.
With resin, however, the body sides stay straight and will stand much more robust handling.
The downside of resin is that it is much harder to glue the parts together the styrene - they do not melt into each other the way the soft plastic does - and the bond is very brittle.
Drop the carriage side onto the floor - as I have been known to do, alas - and the shock it will break it clean apart.
Anyhow, it's not looking too bad, is it? Time to make the floor / chassis now.