Michael Gisiger 
THIS! I'm amazed. #Olleewatch
Works with the following #Casio models:
F-91W, A158W, F-84W, A159W, A171W, W-59
Unfortunately, none of these models have metal cases made by #SKXMod (yet).
Velocipede Rider@joeycastillo The above ⬆️ might also interest you I suppose. If #SKXMod do this, you could potentially have a #SensorWatch board in steel case with sapphire crystal display.
See https://www.skxmod.com/collections/f-105w-mods for their current F-105 mods to get some idea of how this would look, or here is a video to one of their completed builds
Spending $190🇺🇸 (174€ / £148🇬🇧 / ¤1980🇳🇴) on a fully modded #Casio 3298 module† probably sounds a little excessive but it is actually hard to find a retro styled, steel cased, LCD digital watch with sapphire crystal, so that is what I paid yesterday.
† The 3298 module is the one in the A-168W, F-105W, and W-86 series watches (any one of these costs ≅$21🇺🇸). Functionality wise it is just like that found in the famous F-91W, albeit with the superior “Illuminator™” backlighting.