Many thanks for your help - the situation is improved. The images are displaying as full size within each post, and it seems that all images are being displayed.
I'm still a little confused. When I created this layout a few months back the images would display as thumbnails at the bottom of the post and then when clicked open into a slideshow. I will look for the original wp-types support thread which suggested this approach so that we can discuss further, but in the meantime, if you have any clever ideas I'd love to hear them 🙂
Glad to know that images are now started displaying.
I can not tell whats going wrong on your install until I check why images displaying in full size. It would be great if you can share more details with your issue with new ticket.