Early Casios (Casiotron) | Wrist Sushi - A Japanese Watch Forum
The Casio Vintage Club | Casio Casiotron 01-501(01), release date 1974 November, this is the debut model, the beginning of Casio wrist watches, the very first model
Casio 01-504 Casiotron Liquid Crystal Digital Quartz Watch For Parts NSR3012ARB1 | eBay
Vintage Casio Casiotron 04-504 Digital Men's Wristwatch | WatchCharts