That's a beautiful animal, no doubt about it. However, it does appear to have at least a little nominate triangulum (Eastern Milk) influence in it. That may or may not be the case, though. I have syspila from the heart of their range that have the characteristic nuchal blotch connected to the head-cap. It just happens sometimes. The other options (aside from being an aberrant syspila) include being a nicely colored nominate triangulum or being descended from animals collected in an intergrade zone (parts of Iowa, for example). I seriously doubt that it would be a man-made cross. If anything, it's likely to be a natural intergrade. I'd suggest trying to get photos of any siblings to your critter by contacting the breeder. Post anything you find up here, and the lot of us will try to sort it out!
Regardless, it's a nice looking animal.
-Cole