I reworked the original spool holder to give enough room to center mount my cooling fan mod. It prints in two parts and is connected with a couple of threaded inserts and m3x10 screws. I also used acetone to weld them together.
Cooling fan: https://www.prusaprinters.org/prints/147981-voron-v01-electronics-bay-cooling-fan
The author hasn't provided the model origin yet.