Well, the changes to Bell Leisure's site seem to have helped a great deal with their Google listings. The site is now split into two sub-domains, one for swimming pools and one for the snooker and pool tables half of their business.
This has also made it possible to list the two almost-separate businesses as separate items in Google's Local Business Centre. This means that Bell Leisure appears nicely for relevant searches for either part of their business.
However, even with the subdomains being listed separately, Google was still returning the "top level" page for searches. I've now moved the descriptive text from this page, and into the two sub-domains, in an attempt to make the subdomain home pages be listed first.
We'll see what happens!