The MinuteFett files appear to be built from scratch, based on dimensional data from a scan of the Keeler blaster, not printable versions of a scan of the prop. I purchased them and they are well done in general and it's nice to know the size is exactly right.
The modeler did take pains to capture the eccentricities of the original blaster - crooked hexagonal barrel collar, asymmetrical scope ring edges, among others. However there are some missing subtleties particularly in the grip, with edges which are sharper/flatter than they should be, particularly on the right side and the area above the index finger. All things that are hard to model, and that can be added quickly by modifying your print with hand tools, though. The renders in the listing are an accurate representation of the printable model and you can see the flatness of the grip.