This piece has all CAD modeling and PBR texturing of a Commodore 64C model of C64 computers. C64C models had new case design with new motherboard and SID chip (model 8580). They released in 1986.

https://en.wikipedia.org/wiki/Commodore_64#Commodore_64C

Whole CAD modeling process with calipers of the device with Solidworks can be seen by here:
https://www.youtube.com/watch?v=1QpwbB3IvRM&list=PLXfmekZqahrWs7Z9Ye7cjLEMmyIHm322X

MP4 - 1920 x 1080 - 60 FPS