This is a remix of “This Does Not Compute’s“ design, you may want to have a look as well.
It has a lower top edge (I suggest to print the model upside down with supports) and changed base. If you need perfect match to the iMac 27" (2017 and later) you may need to decrease the hight of the model by 2-3 mm.
Enjoy
The author remixed this model.