Strictly speaking I'm no longer stuck, rather than unstuck, of course.
I'm short of time this week, but snatched a couple of hours this morning and did pretty much what I said I needed to do, ie added a bit of blue and put some verticals in where I had a horizontal. I'm pretty happy with where I have got to.
And it works from all angles, I think. Here's a different view.
As it stands this is now about 60" square. There is a chance I'll stop here, but am toying with the idea of going round once again, if the fabric will stretch to it. I am now completely out of the pink shirt as well as a couple of the other fabrics. I have added a couple of new ones in the outer pieces but may still not have enough for what I have in mind. I guess I'll just have to give it a go and see what happens.