Where to buy window track felt

I am actually looking for the felt piece that goes down inside of the actual door. But when I just went out to the car I realized I also do not have these pieces. ole Dart is coming for my paycheck again!

Be aware; I couldn't find a way to replace the guide without damaging something else, and had to remove the window frame etc from the door. I found it quite challenging.
I hope someone will pipe in with an easier way.
There was a very helpful post on this site, I couldn't find, and I think "Hot Rod" magazine had a good article.
Now you need - good luck,
Cheers .