It's just a replacement case. I fell into this rabbithole a little while back- if you have steady hands and don't mind picking up a few tools, it's easy to custom assemble a Seiko. Snag an appropriate movement (NH35A, NH36A, NH38A), dial, and hands and you're off to the races. The only thing that's a PITA is pressing a crystal in, but the rest is just steady hands, some Rodico, and a few tools. And swearing.
https://watch-modz.com/product/skx00...ai-conversion/
https://watchandstyle.net/collection.../sandwich-dial