Now I need a gallery solution and the options at first cast are Media Gallery and Node Gallery.
As I have Media already installed investigate that first but download Node Gallery anyway. When I go to activate Media it reminds me it needs Ctools (Chaos Tools) installing to be able to activate it. Ctools has lots of options so start simple and only activate Ctools and Media itself, which tells me I must activate its File Entity option too. Again there is lots more to investigate.
Media Gallery appears to be mutually exclusive with the Insert Module. If I choose the File upload widget to be Media browser I lose the Insert button, if I choose the File widget I cannot browse the Media Gallery. I will devote a bit more time seeing if they will integrate before disabling and trying Node Gallery. And decide to disable for now.
Activating Node Gallery shows me that I need two more modules Entity and Entityreference. So download those as well.