If you really want the retro experience, you can get a modern USB version of the original IBM Model M keyboard from Unicomp (https://pckeyboard.com). I believe these are made on the same equipment that made the Model M back in the day. Buckling spring keys, metal frame, huge, heavy, and loud. Lots of configuration options and the only lights on them are the (admittedly annoyingly bright blue) lock status LEDs. I’ve used an original Model M and own one of these. They’re amazing.

Oof! Guess I should have looked at that.

Not sure if this meets your needs but you might check out DoorBird. They claim to work with several NAS solutions and have an API, as well as the usual phone- and tablet-notification and communication through their own service.