Since no one knows how many of one color combo they made, it's tough to say wether or not a triple black (TX9) combo is worth more. I beleive they made more triple black 70 cars, but when you add SE into the equation, the numbers start to diminish, ESPECIALLY when you talk about an H51 factory sunroof car. WOW.
Then when you put the combo in with 71, now you are speaking of a rarity. Black was not a popular color in 71, the higher impact colors were much more prevalent. But back to the main issue, it can only be a 70 if it is a true SE.
I have only ever seen 2 true triple black 71s. My friend owns a true triple black 71 RT. HIs car was just appraised pretty darn close to the 60K margin, even though it is just an auto trans. Granted he has the matching 383 block. As a 70, consider the value like any other car, except add a percentage given the sunroof and SE package, and maybe tack on 5% for color combo.
Dan