A quality 6-point racing harness hardware set as you would expect from Scale Motorsport.

Photo etched nickel silver and Includes detailed instructions with drawings.

This includes a textured belt material that has to be cut out and colored (see photos above). 

Here is a close-up view of the belt material so you can see the texture.

Or use the belt material as a template to cut out your own belts.

My seatbelt material will fit, but it's tight.  Cut the belt material end on a diagonal to insert into the buckles and always cut the material with a sharp x-acto knife - sissors won't work. A touch of Future on the tip of the material will keep it from fraying and make it a little stiffer to slide into the buckles.

One package of 6-point harness hardware by Scale Motorsport, 1/24 scale.