There's one for sale down here (Houston, TX) on craigslist. Been up for a little over a week. Pictures show some work has been done to it, still needs more. Here's the link to the ad, hope this helps.
Here's the add listing in txt:
1970 Plymouth Roadrunner
This is a rolling project.
Has motor and tranny.
No tire kickers, this is a project. What you see is what you get.
The car needs body work.
Floors are very solid except trunk. It has rusted through.
Fenders are solid. Has typical rust spots around back window and rocker panels.
Not sure what engine it has. Might be a 340. Never took it out to check.
Price is very negotiable. I will consider any reasonable offer.
$4000 or best offer. Eager to sell.
No trades. Cash only. Clean clear title.
Click on link for pictures.
Car is at a friends body shop.
Ortiz Body Shop.
Houston, Tx 77093