Looking for this part or substitute

Double hung Pozzi window. Company out of business. Purchased by Jeld Wen. Customer service, no help. Part is a plastic block one half inch square by 2 1/2 inches long. Is attached to balance spring by clip which has separated. Part holds the pin for the window. Would appreciate any help. Only looking for one part but would buy multiples if reasonable.

Tom, you are a genius! I think this part will work perfectly. I have ordered five. Thanks for your prompt reply and being so helpful. Thank you. FJB