I acquired my first own "proper" keyboard, an Apple Extended Keyboard II, aka. AEKII. It is well-worn but fully functional. Here's Chyrosran22's overview of the model and his redux review on it a couple of years later (YouTube).
The keyboard has these "ivory" Alps switches that have dampeners in them, although it is still very loud compared to any rubber dome keyboard. My one's obviously the Finland/Sweden model.
The keyboard was filthy when I got it. It might've spent some time exposed to the elements, as the chassis was full of pine needles. The previous owner had also tried to reduce the almighty clatter of the space bar by inserting pieces of double-sided tape under the ends of the balancing bar. I took care to remove the tape.
More filth:
Here's the keyboard with all the keycaps removed:
I proceeded to clean the keycaps with soapy water and a bit of manual scrubbing.
As the keyboard is an Apple peripheral from the nineties, it uses Apple's ADB protocol. There were a couple of commercial ADB–USB adapters available during the transition period, but the differing layout compatibility is a bit hit and miss. I ordered this Arduino-based adapter from Japan, but I have since forgotten the details, and cannot trace them back. EDIT 2024-05-21: I found the details. It is a TMK ADB to USB converter.
This post was retroactively compiled on 2024-01-04 from photos in my photo library.