I agree with you. Eight Thirty looked a lot like his great-grandsire. Again, the blood of Friar Rock (half brother to both of Man o' War's parents) was within a couple generations back in Eight Thirty's pedigree. On their dams' side, Eight Thirty and War Admiral shared a bloodline. Bathing Girl was the third dam of both of them.
Speaking of great-grandsons that resembled Man o' War, champion Stymie certainly falls into that category! The broodmare sire for BOTH of Stymie's parents was Man o' War.
And then there is Kelso, yet a third great-grandson. Kelso didn't look much like Man o' War and left no breeding legacy since he was a gelding, but it is hard to imagine the sport without him.