how to repair 23 yr old pella window blinds (fabric) that open and close with cord.

Call a Window Treatment store and ask them if they offer repair services or whom they usually refer. They're not really complicated devices, but the parts aren't readily available to the public. A good number of parts can be taken from the cheapest blinds at the Home Improvement stores. I only had to do it a couple of times, but it worked perfect and was only $5 each time.