Thanks for your thoughts.
Yes, he ticked all the boxes and we seemed to get on well and have lots in common by mails, which is why I was so surprised he didn't appear to want to negotiate another night, especially as we had already discussed (for instance) a Tuesday evening and he seemed ok with that. Sadly though, Sunday evenings really aren't good most weeks as I work in a hospital and need to be up earlyish and 'with it' most Monday mornings. Perhaps I'll mail him again ... hmmm. He's probably found another bass player by now though.
The other thing that niggles away a bit that we hadn't discussed is that as he plays professionally for a living. So I do wonder how many solo nights he might be prepared to sacrifice for an occasional band gig. He knew I wanted the band to gig but hadn't really got around to discussing that properly.