Since I screwed up the initial post, let's start with the basic facts:

1. All 'R'-code 428-equipped Ford or Mercury cars came with Ram-Air, from the factory.
2. In the specific case of 1969 Mustangs, this Ram-Air took the form of a through-hood ('shaker') induction system.
3. In all other 1969 car lines, an under-hood ('sealed flapper') system was used.

So, while your car should have Ram-Air clearly it has the wrong set-up for a Mustang...most likely a Fairlane or Cougar system that was swapped on by a previous owner. *

Why? Well, its not a new idea for folks to strip off bolt-on, desirable HiPo goodies - like a shaker - when selling their car, if only to maximize their profit. And theft of these items is yet another time-honored tradition. For most of the past 30 years finding a replacement a shaker has been a difficult, expensive pursuit. So, if a compatible underhood system just happened to come along at the right price...

Sorry for the botched explanation, earlier. Hope this helps.

Mr F

* As you'll see in this related thread, using underhood Ram-Air on a '69 Mustang is not such a far-fetched notion. But, before you get any wild ideas, please read my post carefully. And let's recall that 1969 production began in the Summer of 1968. So, a unit assembled in April of '69 can hardly be considered 'early'.