you can't ID it from a photo, you would have to measure it. I did notice that when I pressed the D crank apart to make the 504 D there was a small divot on the inside face of the crankshaft. Chances are if the guy won't measure it, he's not going to take a macro-photo to see if there is a divot on the inside of the crankshaft.
Daniel, if you want to educate the youth, quit being wrong.