Drawing assignment

I don't think I've mentioned before, but I'm enrolled as a student of the Art Instruction Schools in Minneapolis - this was the school that trained Charles Schultz, the creator of the Peanuts cartoon. It's a distance education course where you work from home at your own speed and mail in the finished assignments for grading. I'm just finishing up my "Drawing Objects" lesson, and the final assignment is to draw a sight-size (it's the same size on the paper as it appears to the eye) shoe. This is all set up on my studio table, so until I finish it, it's the ONLY thing I'm able to work on - don't know if that's a good thing or a bad thing.

Here's some photos of the setup, the shoe, and my progress on the drawing. It's still far from complete.

The difficulty with drawing from life rather than photos is that each eye sees a slightly different image. For instance, the dark inside part behind the main strap isn't visible in the photo since it was taken from my right eye perspective.  When I had the camera lined up to my left eye perspective, the toe straps took on a completely different arrangement than what I'd drawn. It's a challenge to combine these two images.