I have some experience disassembling/replacing belt straps on my mid-70's cars whose retractors (and, belt straps that are stitched in a similar fashion) were used for assembly. Your video does not show that the new straps were stitched on either end when reassembled. This is not safe by any means...and, could lead to failure in the event of a collision. The heavy duty stitching from the factory is there for a reason...and, it's not something a person can do themselves unless they have access to a heavy-duty sewing machine and care to take on the risk. In fact, I found it impossible to find a local tailor, shoe shop or auto upholsterer who would do the work due to liability issues. There are, however, a handful of companies nationally that are in the business of replacing belt straps and even restoring the retractors.