This Casio 31SQ-11 dates from around 1977, I bought in a job lot of Casios’s (See photos). It was this one I wanted in the lot so old everything else and kept this one by that point for free. It required quite a bit of work in the end to get it to run and then I polished the case to give it the shine back. You can watch the service of this watch on my YouTube channel here Vintage Casio Service
Here is my vintage digital watch collection as of March 2024
