These imperfections does not mar the model in anyway and with the knowledge of modeling can be worked out of the kit. A big percentage of the models are hollowed out, that are what the drain holes are for and some pieces can be solid also. The drain holes can be puttied in and sanded to match. The models are printed no less than 2mm walls so they are thick. All models go thru a post-production process with sanding and using fillers for any defect that can be found, sometimes they can get over looked.
I try to put in your hands a model that is ready to prime and paint. Color of resin and filament may vary. Anytime you want a tighter fit, the resin part can be heated up with hot water or a hair dryer and it will make it easier to take a better shape. Just don't overdo it.