There must be a fix short of dismantling the GH. Wasn't that one of the last things that went on? If it were me, I'd call the manufacturer and explain the damage, and see what they suggest.

The windows are Pozzi and still in good condition (other than the seals!). I am guessing that the door is Peachtree because that is what the other doors in the house were. Because the door sizes have changed, the price to replace all the glass is way under what a new custom sized door would be. We have replaced all the other doors in the house and had to have custom doors made. We replaced 2 of them because of issues with replacing locks and handles. The other doors were replaced because they were sliders/french doors that were just not holding up well. This door is seldom used in a walk out basement and still works fine.

millworkman -I seem to recall that the installer offered life time support should anything go wrong with the windows. Part of that was obviously product support and coordinating delivery etc. But also the guarantee wasn't valid unless they installed it. I feel that the installation should be sorted by the contractor - is that usually not the case? Also, another incident, the contractor refused to deliver us the correct window sash (for one of the 22 windows we ordered) which they incorrectly ordered and installed. We chased them but the response was that they no longer work with the manufacturer so we should just call them directly and get one from them. We PAID for the sash. They didn't deliver despite numerous reminders and requests. Where are we on that? Any advice? I feel let down because we thought very highly of the business owner.

No. Torsion springs are sized based on the weight, style, and track of the door. Each side is a different length for optimal balance. You do not want oversized, or obviously undersized, springs as it can damage the door, opener, or cause injury. If you are doing this yourself the best method is to buy the exact same size spring. I don't see how the cost difference would be a big deal.