Try your local upholstery shop.
I had to rebuild my whole assembly.
The track was not secured well deep within the pocket.
That was fun to fix.
Anyway, my local upholstery man was able to make me a new strap and he even was able to resuse the hardware (the reinforced hole) from the old one.
Mine was just a piece of cloth webbing.
2009 Flagstaff 8528 RKSS
2007 Toyota Tundra DC 5.7L V8
Pullrite Superglide 14K
Air Lift 5000
Prodigy Brake Controller
"I've got a mind like a steele.. a......a steele......um.....uh...... what's that thing called again?