Some examples of what I've sculpted so far --> https://tombetthauser.github.io/societyofobjects/images/
[1] https://www.computerhistory.org/collections/catalog/10263098...
[2] https://www.computerhistory.org/collections/catalog/10276629...
I’m sure you’re after a model 100 but here’s a link as an example. https://sketchfab.com/3d-models/trs-80-color-computer-2-865e...
Unfortunately, I can't help you with dimensions.
Is the sculpting process destructive to the machine in question?