This was a great project and a quite early Casio model that were produced from 1977. I bought this in a job lot of Casio’s and only wanted this one. I was able to sell the 5 others and make profit so this Casio in effect was free. It needed some challenging work as I had to fix a track as one of the segments was not displaying. I made a full video of the work on this watch which you can find here. https://www.youtube.com/watch?v=T3NBUyX5_LA&t=1176s
All in all a nice digital watch that I learnt allot from.
After posting the YouTube video I was contacted by a viewer who had the same watch given to him by his father in the 70s, his father had sadly passed and his watch did not run. He asked me if I would take a look as it held great memories for him and his father. I happily agreed and was able in the end to fix his! it took some doing but was pleased I could reunite the watch to its owner knowing I had just made this guy very happy.