$5k is too much for that car, even as nice as it is. No matter what, its a 1974 /6 Duster. So I don't understand the "keep it original" posts. It's not rare at all. Not even a little. Wanna ask how I know?
Looks familiar right?
This is my '74 /6 Duster after I brought it home, waxed it up and put new rims/tires on it. Now, I also had converted it to a 318/904 at this point, but you can't see that. Mine looks like it has some more shopping cart rash than the one the OP listed, but it was a little old lady car the majority of its life too. I'm the 4th owner, but the 2nd and 3rd owners had the car less than a year each.
I paid $2k for my car with the original /6 in it. It allegedly had 91k original miles and "carb problems" that turned out the be a dead cylinder. But I did actually drive it around the block a couple times before I bought it. I swapped in a running 318 because I already had a V8 K frame. And when I got tired of the 318 (which was more worn out that I thought) I dropped in my fully redone 340.
That said, if you can talk the owner down on the price, it looks like an awesome, solid car. If the /6 runs well, I'd just go through it, get the suspension and brakes up to speed, and drive it until the /6 gives up the ghost or until you get tired of it. As far as keeping it original, there's really no point. Any modifications you did to the car- converting it to a SB or BB, upgrading the rest of the drivetrain, etc, is only going to make it worth more.
They look like really similar cars. Here's my build thread on mine....
http://www.forabodiesonly.com/mopar/showthread.php?t=198098
The day I brought it home...
And now...
