This is a combination of the remixed items and this https://www.myminifactory.com/object/sheikah-slate-shell-30864
I did not see any sheikah slate cases for the switch available to print, so I took the aforementioned myminifactory file, and modified it using what little modeling skills I have to make my own.
This is a cosmetic item, not a protective case. Some sanding is required for the side rails.
*Disclaimer. This is not a protective case. I am not liable for any damage to your Nintendo Switch.