I e-mailed ECS about availability and price of a flat shipped carpet kit for my 1964 Plymouth Savoy 2 door post (early b-body). This is the email response that I received:

"Hi, I checked into this and we don't carry carpet this far back in our custom style. Thanks for checking with us. Please let us know if you need anything in the future."

Thanks,
Cindy
ECS

So much for a flat shipped carpet kit from ECS for my car. I called Motor Parts South, and they DO have carpet available for my 1964 Plymouth Savoy (early B-Body). I was pleasantly surprised how reasonable their prices are. They also offered to customize the carpet for superstock style, with rear seat delete and heater delete, for only an little extra.