Milton explained the situation pretty well (Thanks for that, man)

Real life's been getting in the way and my motivation's been pretty low for a while. I started work on this plane 3 years ago, and to be honest I don't really want to work on it again. The model is finished. There are parts of it I'm unhappy with, mostly leftover from when I first started work on it (This was the first model I ever made), such as the windows in the bow section and the vertical stabilizer's rather unsightly mesh. There are also some missing details like gauges for the flight engineer's panel and fuel controls, as well as the windshield wipers. Other than that, I am quite happy with the model. But at no point in the last 3 years did I even begin to program it, and it's only been UV mapped recently (though the current map might not be great for FSX).

If anyone wants to finish this project, and I really hope that someone does, do not hesitate to contact me, and I'll send the mesh as well as the pilot's manual for this variant of the aircraft

Sincerely,
-Matt