In the wedding scene we hear and see Mama Corleone yell out "Nazorine" inviting him to sing, the scene switches to Sonny and Lucy and then it switches back and we see that the old man is singing. So there was speculation that he could have been Nazorine's father. But now we know that it wasn't because of the two scenes that I mention above.

I never said that he was Stracci. But the short animated Don who was shot in the elevator IS the guy that gets out of the same car right before the old man.