Going to a Mopar Gold Mine...

If any of the convertible stainless trim is missing on the car then it will cost a very shiny penny for those parts. Difficult to find. And gone FAST when available.
I've only seen the one picture. The guy won't release more pictures or info to me until "someone" makes a play at the car. I told him to let it go to the local first and me second if that be the case.
I say 18k cause I'm a cheap *** and 18 would be worth it. Possibly as much as 28 if someone just has to have a convertible. Honestly with the fender tag gone and no build sheet, NOM, no window sticker, no provenance on the car I would definitely be more in the lower range for the car.
The additional parts that come with the car might make some difference on price also.
This car will cost no less than 30K to put back on the road in shiny newish condition.
To restore the car properly, 60K. So, 80K when the car is done to restoration standards but the car will only be worth around 65K, maybe 70K to the right person.
If you were to take it to the promod level of build, you might be able to squeeze 120K out of the car. After putting 120K into the car. I have no experience in this type of stuff. I do watch the market though.
Challengers are nice, but their pricing just doesn't hold up to the cuda's. A cuda like this would be, say, 27K to 40K depending upon the car.