Welcome aboard Andestang :-)
So going by Anghel restorations article '69 did not come out with a rear deck lid spoiler but always see references to '69 specific spoilers. All the re-pro deck lids that I see seem to follow the '69 version. My Mach has a spoiler but is clearly the wrong one and would later like to identify what it's from ( it's mounting stanchions are narrower, mount right where the hinge channels are ). But for now in my search for a correct one a bunch of questions have come about. This comment from Jeff on another thread heightened my questions.
quote "The 69 mounts to the mounting arm with rivets in 69 and screws in 70. Also the wing is made from different material. So based on the pictures it does not appear to be either a 69 original or reproduction. Mounting (to the trunk lid) is different in hardware also.
Both the 69 and 70 will fit the same mounting holes as well as "look ok" from a distance other than an original 69 will normally have the warped shape by now."
It appears that one was offered in '69 but only as a dealer add on ? Does this also go for the rear louver ? Material differences between '69 and '70 ? I see about the stanchions rivet vs bolting. If it was a dealer add on, what was the usual method to install if the oval mounting hole was not on the original lid ?
My understanding is that the '69 rear spoilers were a "boss only" item for '69 mustangs ('69 cougars only got them with the Eliminator option). But it was an item the dealers could order and install themselves, which is what they did sometimes...
Most of the reproductions I've seen are based on the '70 spoiler.
Here are the basics on the '69 vs '70 spoilers:
1969 Rear Spoiler - basically PVC, hollow and light-weight.
- '69 Cougar and Mustang rear spoilers are different, due to pedestal spacing.
- Pedestal spacing is 31" for cougar and 36" for mustang.
- Pedestals themselves are identical between mustang and cougar, and appear solid-cast on the bottom.
- Spoiler Wing is pop-rivetted to the pedestals for both mustang and cougar.
- Mounting plates inside the trunk are different between mustang and cougar (and also different between '69 and '70).
1970 Rear Spoiler - made with fiberglass reinforced sheet moulding compound, essentially solid fiberglass and heavy.
- 70 mustang and 70 cougar rear spoilers are the same.
- Pedestal spacing is 36" for both mustang and cougar.
- Pedestals are cast differently than '69, and appear "hollow" underneath where the part number is located.
- Spoiler Wing is held to the pedestals with screws, brackets, and plates.
- Mounting plates inside the trunk are different between mustang and cougar (and also different between '69 and '70).
1969 cougar rear spoilers don't fit anything else (at least not correctly). The '69 and '70 Mustangs used the same stand widths (36"). The mustang mounting hardware under the trunk lid is different, due to differences in the trunk stamping - the same goes for the '69 vs '70 cougar spoilers.
So measure the space between your pedestals. If they are spaced 31" and rivetted to the wing then you have a pretty rare piece.
I hope that helps you some, and let us know what you learn about your spoiler!