Found a company doing a novel new trick, well new to me anyway.
They scanned my authority website for dead links
Then put up some content relative to my dead outbound links on their own site
Then email and ask if they can quote my site with link back to me (naturally I agree)
When I confirm it’s ok they tell me about the dead link saying they know how hard it is to run large important sites and monitor everything and offer their (new) page as an alternative link.
I can see that working for them.