Hello, <<<Too early for Arvinode exhaust, should have been a transverse system.>>> I have been in contact with the original owner and he states that nothing was done to the exhaust on the car from the time he picked up the car, until we purchased a few years later. Also, he did not drive the car enough to replace tires, brakes, shocks or any other consumables.
I can say that the original exhaust on my car did NOT have the rectangle supports on top of the 'mufflers', the exhaust system was one pc. from H pipe back to the turn downs at the rear valance.
The car does have the 64 1/2 hood & headlight buckets, heater switch, spare tire bolt. The car is Rangoon Red with red interior.
Keep in mind that 50 years is a long time. Previous owner's recollections are not always accurate.
If your mufflers do not have the rectangular tops, then those are not Arvinode mufflers. I think we need to see a pic of what you have. The only factory dual exhaust used on the assembly line for K codes at the time your car was produced was the transverse setup.
Not sure if you are aware, but your car is most likely a pre-production example. Meaning, your car may have been built before the re-start of Dearborn for the 1965 model year. This was the conversion/re-tool time from 64.5 mustangs (generator cars) to regular 65 (alternator cars). Dearborn re-started the unit numbers with 250001. Same sort of thing that happened earlier at the beginning of mustang production. Any of the cars with 05C scheduled build dates were actually pre-production cars and not actually built that day. 09C was the actual first day of assembly plant production. I have not studied the 64.5 to 65 transition, but 01H scheduled build dates could be used the same as earlier, to designate pre-prod.
If I were you, I'd examine the car very closely looking for anything that appears different or out of place. It could have been a show car or some special use. What's the DSO?