I am in the process of shopping for carpet for my '66, I have received carpet samples from Millers and World Upholstry (
http://www.worlduph.com/). I have determined they use the same carpet, I can not discern a difference.
I have white exterior with the red interior, I've played with the idea of using grey square weave, but I keep changing my mind back and forth between it and red. I think the light grey carpet would look great with maroon as well.
World Upholstry does show a maroon import loop, their number 1478.
I could save $150 - $200 by going with the import loop, but I really like the square weave.
Democracy is two wolves and a lamb voting on what to have for lunch...