That one was posted first—you can tell this from e.g. https://news.ycombinator.com/submitted?id=arbesman, or just from the ID number in the URL. But its timestamp got relativized by the second-chance pool—see https://news.ycombinator.com/item?id=26998308 and https://hn.algolia.com/?dateRange=all&page=0&prefix=true&que... for explanations.

Also, it had the original source (https://www.wbur.org/news/2024/12/16/400-years-zildjian-cymb...) that this one points to.

Your post was great though! We just try to pick the earliest one (and/or the original source) when choosing stories for the SCP.