Raid your womens make up department. My wife uses these puffy very soft bristled brushes for God knows what but they are perfect for dusting off models. I have all of mine in a glass case and they still collect dust but these make up brushes work great.
Blown air works, but over the years you also get a "grime" that comes from things such as naturally emitted oils, cooking, smoking, and in B-17s case brain emmissions. .