Jason,
Try comparing it to the nose contour of an E6. According to the Summer 2012 issue of Classic Trains (with a special section on E units), "Produced exclusively for the Burlington Route, [the E5] was basically an E6 sheathed in stainless steel." The picture on page 27 of that issue shows CB&Q E5 #9912-A had the slanted nose. If I had to guess without putting a ruler on it, the model (at that angle in the photo above) looks like it may not be slanted enough, but it's definitely angled more than an F unit.
DFF