Hello CHIEFER69,
It is a possibility that you could have a factory sunroof. If so, that would make your Mustang a rare car with an extremely rare option. Ford never offered the power sunroof as a regular production option (RPO) on the Mustang. Ford probably figured since the Cougar was more upscale and luxury orientated the sunroof would sell better on the Cougar rather than the Performance-oriented Mustang. Since Mustang/Cougar shared the same assembly line it was certainly a possibility to get any Cougar option as long as it would physically fit and if you had the $$. The sunroofs were installed by American Sun Roof Corp (ASC) and had been on the Cougar option list since 1967.
Since you already have a Marti report and it doesn't show it or the DSO order code, it's looking more to not being a Ford/ASC sunroof. Marti Auto Works also offers a copy of the actual invoice Ford sent to the dealer. So if your car was drop shipped to ASC it would be on the bottom of the invoice below the ordering dealer address. Your door decal would also show a four-digit code after the two-digit DSO code (which is not on your report). The majority of the special orders on the car line were for other than RPO paint options. Anything not in the Mustang option list would be a special order.
The roof panels were metal and also normally required a vinyl roof.
You could also check the power roof switch and see if there are any ID numbers on it. If it is an ASC/Ford top then the switch could have an ASC part ID# A5AA-321-0031 or Ford part ID # D1SX-15B691-AA.
I have very little price info on the Mercury line but the power roof option on the '73 T-Bird (also an ASC installation) was a little over $500.00 so I figure the Mustang to be in the same price range.
Hopefully, this will help you further determine if your sunroof is Ford or aftermarket.
Thanks for the information Secluff! The reason I'm having a hard time on this is because once I get it back from the mechanics, my dad and I are going to be starting on the bodywork. We have the original gauge steel for it. The sunroof pops open and works fine with no leaks. If we take the sunroof out that means cutting and welding the steel back in the hole. I know based on all welds that it can and will have warping of the metal. Come Monday, I will go to the mechanics and see what kind of sunroof it is so I know if its an after market or not. If it wont affect the value much and makes it a more rarity of a car I was just going to keep it and start on the bodywork with it on there. If not we were going to take it out and cover it back up