How about buying some cheap industrial carpet offcuts, use the old carpets for templates to cut them.

You can then have the colour you want, and the style of carpet you want. Some areas will need gluing with a good carpet spray adhesive, but it is not expensive.

One of mine had offcuts from a carpet fitting place, it was industrial carpet and bullet proof. It has had every form of abuse and was still in good condition when the vehicle was sold.