Did every 1974 Gold Duster have a resonator?

Hi All - It's Bob again, the guy researching the correct exhaust system for my 74 Gold Duster. I've learned that the optional Deluxe Sound Insulation Package always came automatically as part of the Gold Duster package in 1974. Since the exhaust resonator was a part of the sound insulation package, this meant that every Gold Duster in 1974 came from the factory with a resonator. Does this sound right? Has anyone ever seen a factory resonator on a Duster? I've attached a photo of page 11-2 of the 1974 factory shop manual that clearly shows the resonator as part of this exhaust system. IMG_0887.jpg I know that Accurate Ltd. will sell you a complete exhaust system with a resonator for a 225 Duster for $684.00. Seems kinda pricey. Whaddya think?