Hey @ihor,
Thanks for replying!
I tried using the snippet you linked to above. However, I found my custom additions are added below the search bar, and changing the order didn’t seem to help. The version I quoted before was allowing me to add my custom additions above the search bar, but, after some more testing I found it ‘bled through’ onto the pages that show once you click a category and the category header is the top of the page.
So, unfortunately, neither of the snippets are working exactly as I’d hoped, so I’ve removed them for now. Is it possible to either use my snippet and ‘stop the bleeding’, so it doesn’t also show on the category pages? …Or, use your snippet, but allow for additions above the search bar?
I hope that makes sense! 
Cheers,
Chris