This is the original post I added the model in, https://github.com/Xinyuan-LilyGO/T-Display-S3/issues/36 so please link back in there if you improve, or here if you remix / make cool things.
Original Comment:
Added version together, including STEP file, STL file, fusion360 fbx project.
It's approximately positioned 1.5mm from top edge and 5.5mm from board to glass surround which matches roughly the unit in my hands, and matches the normal t-displays3 if you measure to the top of LCD.
It is not centered along the midpoint lengthways, but instead roughly positioned (LCD overhangs 0.236 left 0.246 right) YMMV
The author remixed this model.