ROADRUNNER ID

I've been offered a rough but numbers matching 70 Roadrunner.
Thing is, I need to be able to authenticate that it's really a Roadrunner and not just a Satellite.

There's a fender tag and signs of it being a Roadrunner.
What can I look for that will positively identify this car as a Roadrunner????
Will the fender tag decode as Roadrunner and not just Satellite for example.....???

I need something that I can do easily at the sellers place.

Any help here please..????????
Author: raindance654