I work in a facility that provides services to people with developmental disabilities. We have vertical blinds on most windows. We have a real problem finding replacement parts. The "gear boxes" and metal clips are a big issue. When the metal clips come off the ends, the blinds will not close and of course the clips are lost. The "gears" are striped on occassion. Venders in town do not carry these parts. This drives my maintenance man crazy. Where can I find them? They are Graber.