Complex sentence: This was resolved by Korchnoi's allowing the match to be replayed in London, with the match (along with the match Vasily Smyslov vs. Zoltan Ribli) put together on short notice by Raymond Keene.
Split into simpler sentences: This was resolved when Korchnoi agreed for the match to be replayed in London, along with the Vasily Smyslov vs. Zoltan Ribli match. The Korchnoi-Kasparov match was put together on short notice by Raymond Keene.