While not the rarest C body, my old '69 300 convertible is rare.
Chrysler produced only 1,933 convertible 300's that year.
I don't know if there is a breakdown between 375hp TNT 440's...
vs...350 HP 440's built.

I used to have a 1968 Chrysler 300 convertible.
Black with red interior, white top, 440 auto TNT car.
I have yet to come across another one in same color combo, In ANY engine combination. And have only found maybe 3 or 4 drop tops that were TNT cars.

Unfortunately, I lost it in a fire several years back and the burnt hulk was junked. Still have the fender tag as a reminder though!

Funny you should say that. We got a striped 300 Hurst car that someone stole the drivetrain out of and only left front brakes, hood and trunklid. Parted what was left and gave it to my derby buddy who got three runs out of it. Was said to be a rare care because it had a center console and performance axle package.