Cool.
Mine probably falls into the "black back" category. He looks similar to the one in your second pic except his head is larger. Also the babies he has produced all have a high amount of black.
That brings me to another question. You mentioned a 2-year old male that is already 1700 grams...... I have a pair of 3-year-old siblings that are not that heavy and are only about 32 inches. Are they growing slowly, or did yours grow fast?