Ye in time past (υμεις ποτε). Ye Gentiles (Romans 1:18-32).

Were disobedient (επειθησατε). First aorist active indicative of απειθεω, to disbelieve and then to disobey. "Ye once upon a time disobeyed God."

By their disobedience (τη τουτων απειθια). Instrumental case, "by the disobedience of these" (Jews). Note "now" (νυν) three times in this sentence.