I was cleaning my floorboards (genuine Yamaha) and removed the rubber inserts with a light spray of WD-40 on the underside...so you can pull out the little nubs without tearing them off.

First I used the insert as a template on some grooved sheet rubber, then went to one of the big box hardware stores for a mat.
Found an Olefin all-weather nylon entrance mat, 20" x 27" for $3.00, and made an outline on that, and cut it out with an X-acto knife.

Then used some "Goop" on the underside of the fabric piece as an adhesive, and let it sit overnight.