It's still in the green - continue - but monitor it (it's only a single indication) - and especially oil temp carefully. A correspondng variation in temp is reason to return.
I very much doubt any school or engineer would intervene on an indication on an old knocker of a 150 that's allegedly changed but still in the green. After all, what can/could they do?
Last edited by meleagertoo; 5th Jul 2020 at 12:10.