operator

Hello. Could you help me locate what I need. Three of our 1980s windows have trouble with the operators. The right window totally rusted out the bottom link which I cannot see in your models. It seems to be for support. You can see it in this picture. This is the best one. They all should be replaced. If you could tell me what I need and how much will it cost that would be great. Thank you it's the link under the bar with the entry gard name in it.
Rusty piece. The others are very bad and as I said one broke up and fell apart