I found this article[0] that shows the gear he used for the images discussed within, but that was from 2022. He used a Celestron NexStar 8SE with a Canon EOS 1200D. If you really want to know, you can look up the magnification of that particular scope with the sensor size of that camera, and you can see how much of the moon would be imaged in a single snap. That would at least get you a closer guess. However, how much he overlaps is still a question. For this particular final image, it sounds like he's completely overlapped each image multiple times since there's 81,000 images used.

[0] https://www.ndtv.com/world-news/stunning-detailed-image-of-m...