So my 1985 wagon has pre-tensioners. The buckles are broken (not a safety thing, it's the part that keeps the buckle from sliding down into the crack between the seat when you remove the belt, not the part that takes the force) and I'd like to replace them. I assume that I can't slide buckles onto the old belts? Is there any chance that I could get replacement belts for less than the value of the car?
What controls these tensioners? This car was in a front end accident before:

and they didn't tension the belts.
-Tad