The time finally came - it just had to be done. We've put up with cracks in the plaster for quite some time, on the basis that, even if you fix them, they re-appear. But you can only take so much, so we've called the plasterers in.
Work in progress
It's messy (very dusty indeed), takes time and it's not cheap, and while the work is still in progress, from what we've seen so far, we're happy with the quality.