Glad my imput wasn't a total loss. I usually to to make sure and double-check my references before I say something totally stupid, so much for winging it.
The trough is the antenna trough, used to store the antenna when not in use, it is made of wood.
While it probably isn't worth spending too much time trying to improve this kit, one easy thing you might add is the perforated heat shield on the muffler;
While not exactly to scale, simply cutting a piece of PE mesh to fit will do the job.