Theme BlackBird….. conflicting with new theme

I was utilising your BlackBird Theme (Paid for), but have decided that I want to move to an alternative theme (Pagelines) which is now installed on my website, however, I appear to still have some legacy code which is effecting the functionality the website (causing problems with the Widgets & The Blog appearance).

I have uninstalled and deleted the Blackbird theme entirely (through the uninstall function and also checked that it is no longer on my server) but certain elements of its functionality still appear to be operating within the new theme.

Anyone got any thoughts on this? I have emailed Ink Themes, but they categorically state that once deleted no code remains or will effect the WordPress installation…… WRONG!

I have had a look at the SQL Tables (Can I point out that I am NOT an expert at this) and have noticed that there are 3 fields which contain reference to the Blackbird Theme. Could these be causing the conflict and if so, what can I do to resolve it. I am assuming that its not as simple as deleting the relevant data?

I would rather not have to go through a complete fresh install of WordPress

Would welcome all and any assistance.