This is a a view of the frame from the side-handle perspective.

The spindle housing is 5/8 inch in outside diameter and was originally nickel-plated.  After clean-up and polishing, the plating unfortunately did not survive. 

Now it is highly polished iron.  The housing has a provision for injecting lubricant.

The spindle housing view from the gear side.  The "Friction Roll" mounting bracket is visible here.

The inside diameter of the spindle housing is 3/8 inch and will take a spindle of that diameter. 

This is the seat socket for a spindle.  It will house the trust ball bearing on which the end of the spindle with rest.

The seat socket has provision for injecting a lubricant.