After much work, Tony Minieri's adding photos of finished pieces to his website. Here is the first one. See the two thumbnails under the main photo? That is a flag that there is a stitched model image. Click on the thumbnails to change images.
I suspect most of his guides won't have model photos since Tony has to wait for a student to share a good photo with him and if the student made substantial changes to the stitch guide, Tony won't be able to show that as a good representation of the outcome, but it is a nice touch and much appreciated.
UPDATE: Tony also has a Pinterest page where his students' finished designs are posted.