The Arithmeum in Bonn, probably known to most of you, named the Curta their "Calculator of the Month" and published a movie a student made about it, explaining its inner workings in great detail.

Unfortunately the spoken language and texts are in German, but if that's not a problem it is really interesting to watch.

https://www.arithmeum.uni-bonn.de/sammlungen/rechenmaschine-des-monats/archiv/39-die-curta.html

And, by the way, happy new year!