Searching for 26-4cg5 cmc51
I'm afraid I cannot identify what you have based on the stamp alone. That's not an identifying serial number, it only indicates how strong the spring is.
In order to help, I will need a clear picture of the top and bottom nylon fittings and the metal hook at the end of the cord. I would also like you to measure the metal channel and tell me what you get.
Thanks!
I have not received any photos of you since your original post on the 18th. Please make sure that you upload them to this page directly. I can't see them any other way.
Once I have those pictures I will do my best to assist you.
Thanks for your photos. Based on what I see here, you have either our S380-27 or S385-27, depending on the depth of the bottom shoe. That's the only difference between them. I recommend measuring your shoe and referring to our dimensions to confirm the best match.