I got some belts from a 97 extended cab two weeks ago when I bought the doors. The problem is extended cabs used quite a bit different seat belts than the standard cabs. They mounted in much taller pods next to the "B" pillar so they would not be in the way when people tried to get in the back.
My options were to wait until I could find some grey ones for my truck or move the extended cab belt webs into my retractors. After a good soak in some oxyclean the webbing looked nearly new.
The hardest part of this was having the right twists in the right spots on the belts and putting all the retractor mechanisms back together correctly.
The ends of the retractor reels are staked, they were fairly easy to get apart and a little harder to restake.
This reel on the passenger side has a splined shaft which drives a mechanism which appears to lock the reel once it is extended to a certain point, I am no expert on this sort of thing but it appears to me that it is designed to allow the use of a car seat on the passenger side.
The finished belts look much better with the grey seats, Matty helped me paint the retractor covers.
I also got the "A" pillar covers, kick panels, and the close out panels aft of the seat belts painted.