As far as I understand Hunday used a different sized bearing. He just shorted the space and did not mill a new one like you would need with your suggested size of the bearing.
Despite there are bearing with the correct inner diameter (20 mm) and the width of 20,6 mm, i.e. this one 305704-2RSR.
Would this be an option or is the wider diameter of 25 mm needed to fix this issue?