The hole in the center was added as a negative space in prusaslicer, the stl doesn't have the 8.5mm hole in the center for the clock hardware to mount.
I used clock hardware from Amazon
https://www.amazon.com/gp/product/B07VQS81Z1/ref=ppx_od_dt_b_asin_title_s00?ie=UTF8&psc=1
The author hasn't provided the model origin yet.