I was looking for a complete set of oil lines for this car earlier and it's hard to find.

But as for this single corroded section of line, there are offers on eBay, for example this one:
https://www.ebay.com/p/253551847?iid=267236852861

So I bought it.

This section of oil line no. 3 is easy to buy, the other sections are hard to buy. It seems that this section no. 3 wears out the most.