There were a couple of cases that you could look for...
The Apple made ballistic nylon case that held the 2100 and the Newton keyboard. Has the Newton logo stitched on the front.
Neoprene slip case for just the 2100. I can't remember who made it but it is black on the outside and blue on the inside. There's an iside pocket to hold a memory card.
Another option is to buy a CD disc holder case - the half binder size and rip the CD sleeves out from the centre. You would need to make sure the depth of the case is deep enough to hold the 2100. This would give you the operational equivalent of the Apple made case
The Apple made ballistic nylon case that held the 2100 and the Newton keyboard. Has the Newton logo stitched on the front.
Neoprene slip case for just the 2100. I can't remember who made it but it is black on the outside and blue on the inside. There's an iside pocket to hold a memory card.
Another option is to buy a CD disc holder case - the half binder size and rip the CD sleeves out from the centre. You would need to make sure the depth of the case is deep enough to hold the 2100. This would give you the operational equivalent of the Apple made case