Some more questions if you don't mind.

Can you comment on fits & ultimately how things are secured? For example, do you fix the center point to the 2 bearing ID's with a retaining compound & maybe insert the whole rotating assembly into the body cup pre-warmed up or something so it resides in place with a bit of interference?

Would you consider this a use-it-till its worn type tool or could it be disassembled? (Its the reverse of above ^^ that got me wondering about this to begin with).

Sorry I am kind of naive about these 5203ZZ double row angular contact bearings. Does that mean each bearing unit has 2 internal rows & stacking two units together just gives you that much more thrust rating or stability on the center shaft? Is there a left/right orientation to these bearings or they are equal so you can just install them as a stack like you show?