This is an Avant Stellar keyboard, the successor to the famous Northgate Keyboards.
I first used a Northgate Keyboard in 1989, and eventually owned several of them.
They have a metal back and are practically indestructible. For me, this is good.
What's that yellow stick sitting on it? I think I've heard of devices made ages ago to make marks on paper as a means of communication; is that one of those?