Graco lite rider navigator SL stroller broken seat holder clip

I have a graco lite rider navigator SL stroller that is about 15 years old. the seat holder(clip) to keep the child in the upright position, on the right side is broken. the stroller is in good condition. The graco repair place emailed me to say the model is dicontinued and they do not have a part to replace the seat holder clip. What can I do. I do not want to throw it out. It is still very useable if the clip was fixed. Thanks