No for some reason known only to Yanmar they are steel pipes and it is a common problem with Yanmar engines.The pipe looks like copper. Is it corrosion or just dirty ?
You are correct - with starter out it was a fairly easy job to remove pipe. It’s not leaking yet but I suspect it wouldn’t have been long. Found a genuine Yanmar one for £87 incl postage. If you know Yanmar parts costs that’s practically free, so happy days.Oil feed pipe, as per Geem.
Depending on engine access, it is not an engine out job. Ours went a week before the summer holiday, managed to get another for 100 ish (was a few years ago), and fitted it in an afternoon...
Iirc, starter had to come off and some other bits and bobs, but nothing major. Just fiddly. Starter required 12" extension for socket set.
Is it leaking yet?