Hi, John.
I knew I had to be doing something wrong. I finally found it. I was looking at the template panel on the left. It is there on Layout Style panel on the right just as you said.
What an amazing job you have done. I am impressed with the layout and even more so with all the options you created to allow users to customize the gallery according to their preference and/or need.
Fantastic job. Thank you very much for your help and for sharing your gallery with all of us here.