Well, first I gotta tell you I downloaded the model here
http://www.premaircraft.com/B1900D_FSX/index.html, and I sure hope it is the latest release.
Second, is that I use Track IR. Usualy, I only need move my head a bit to the left (like almost touching the window glass) then turn it over. On an Airbus 319 for example, I can see most of the pilot side wing and a bit of the engine. On some models I can even force the head to come out of the cockpit, and on the Beech 1900 I'm sure I didn't see no wings. As far as I'm concern, the VC model, as any 3D model, is a model "of what is to be seen" in there. So usually is has all the cockpit 3D interior, plus passenger cabin interior in the B1900 case, and the wings - no fuselage, no tail. For example, the stock FSX King Air 350 VC, only has cockpit and wings - if you move the eyepoint back past the cockpit door, you'll see only the wings, no cabin. Usually the modeller copy the wings elements from the 3D exterior model and attach them to the VC model keeping its relative distances, for them to be displayed when the pilot looks back to its 8 and 4 o'clock. There are some other models, like say the Airbus 310, that you only see the wing tip, but the VC model has the wings completly drawn, including the engines, even if you can't see them interely. I away from my pc now, but I'll check the B1900D asap, and try to capture a screenshot to show what I see looking to my 8 oc.