[Theme : Gridsby] Gallery not width of post?

Hi there,

Because I’ve wanted to just show the main images from the series of photos I’ve taken on the homepage. I’ve put a gallery into a post, called it an ‘image’ and it works great.

However, when you click on the post it’s shows the main image and the tiled gallery underneath. Problem is that the gallery is only going 2/3 across the page?
Any ideas how to fix?
https://trebuchet.click/legendary-shack-shakers-2014/

Another problem/feature would be if you could roll over the image on the homepage and see the image title.
and/or like the blog widgets on the homepage the title was present (on/off) of course. I hope there’s a way of doing this and I’ve missed it.

Thanks for your help.