Also saw that quote, have my doubts about original 72/737s. Having worked both dont recall 429 on 727-100 or 737-200. Possibly on a very late 727-200 with INS etc.
727-100 EIS 1964
737-200 EIS 1968
737 3/4/5 EIS 1984 - certainly 429 use.
As usual could be having a memory lapse !
HTH