That one should be kept concours!

That's a nice car.
If you are thinking about upgrades that can be bolted on, I say go for it. You can alway put it back like Ford made it. Store the important parts in the attic for the time being.

thanks, 
Yes, I found this near Atlanta, Georgia.  The original owner bought it in July of '65 after he came back from the Korean war.  He parked it in his hangar next to his plane.  He's 87 and only sold it to buy his wife a new car.
Even though the seats and paint are old i'm gonna drive it just like it is, after installing new brakes and rebuilding the power steering valve.  Its definitely not a show car but it's mostly original.  I even found a stack of gas receipts, dated with the mileage written on them up thru the 1980's.  

As far as taking parts off and modifying it but that "you can always return it to stock" trust me it will never happen. I have a truck load of parts I took off my 68 that will never see the road again on my car.
 Replace what needs to be with original spec components. You have a very special find there freind, keep it the way Ford meant it to be.

You would only return it to stock if you were going to sell it and look to get maximum money for it.  So if you're going to keep it forever just do whatever you want.  In the end its your car.  Rare?  Sure, kind of.  I mean let's not get carried away.  Its rarity is in the fact that it hasn't been molested, wrecked, rusted, etc.  If it was say a regular restored car with everything else the same it would be considered nice, but not nearly as holy.  Its not like its an unrestored survivor '68 GT500KR convertible or a Boss 429.  Say it had an I6 instead of a V8, would there still be a call to arms to stop converting it to a V8? 

In my opinion if you own a car, but don't have it the way you really want it out of fear of devaluing it there's no point in owning it.  My problem is that stock, for me, is simply never satisfying.  I don't hold it against those for whom it is; I just know myself well enough to know that nothing in my house gets left alone.  If I came into a car like this at a reasonable price I would certainly buy it, and probably cruise it a bit, but in the end I'd sell it at a profit to finance the projects about which I'm truly passionate.  But that's a decision each of us has to make. 

Wow, great find. I wouldn't touch the paint. Those tail lights though...

Bob

You NEED to drive it down to Panama City/Fort Walton Beach this fall!! I'd love to "enjoy-it" with you in person.
Last year(at the MS Birthday Bash) we "enjoyed" an untouched  67-427  Shelby. Totally original.
We don't see many original paint/original interior Mustangs.
6sally6 

I have a 66 factory GT 4 speed, pony interior ,  The numbers built are really low with all these option.  I added a 5 speed, ac, power steering, 3,55 rear.  Made the car a lot more fun on long bash trips,  Only thing about the mods is I kinda wish I kept the old parts (sold them).   

Exactly.  When I restored my '67 in the mid '90s you put them back to stock.  I remember seeing modified cars in magazines and thinking what an idiot that guy was.  The problem is that stock the car isn't very usable in the modern world where people drive 80MPH on the interstate.  I remember when it was done I thought it was a rocket ship, but I was a naive teenager.  Having since driven and owned vehicles that are significantly faster and handle better the bar's been raised.  I found myself at a crossroads: make some changes or continue to let the car sit unused.  I'm glad I decided to make the changes, because now I drive the car a lot more than I used to. 

thanks guys, the bash sounds like fun!
 

Perry, what a nice find! When I restored my 67 coupes front end I installed 620 springs that were 1" lower than stock springs,1"front sway bar,just a gas shocks,215 70 14 tires,everything else new. It handles very good for a 50 year old
car. New gt leaf springs in the back. You might want to consider this option,still pretty stock,but improved handling.
The choice is yours,some say their only original once,some like to restore them to their former glory (if not better).
What ever direction you go,I'm sure you will be happy. what a great unmolested car.  mustang stu