Posting this here in case someone else is in the same predicament I was. I had a reading light 20 years ago that went on the spine of the book and was perfect for paperbacks. It died about 10 years ago after serving me well on six deployments to Afghanistan.
I have finally found a reading light with the same design that uses a AAA battery. So posting here in case anyone else is looking for the same.
https://www.withitgear.com/products/bind-bright-dimmable-led-reading-light
by promina100