I got my '93 Model M out of a dumpster.
The white box on top of it is a Bluetooth Adapter - Handheld Scientific, and it works great if you want to use an IBM Model M with an iPad or other bluetooth device.
I mostly use this keyboard with my iPad. As you can see, it's in need of a good bath. When I get around to cleaning it, I'll replace this paragraph with a link to how to clean an IBM model M.
This one is one of the newer model M's made by Lexmark, and has the one-piece keycaps.
Specs:
Layout: 101 key
Label: blue IBM logo
Cord: detachable
Keyboard Number: 1370477
ID Number: 5009085
Manufactured date: 06/04/1993