Bridgeport bearing locknut size?

[OldMachinist]

Randy, I can get the inner thread size from the shaft but don't know the amount of clearance between the inner and outer locknut.
Also, the outer nut has a shelf with a lip inside it. Does the inner nut screw down and contact the lip or is there a groove cut in the
bottom so it sits over the lip? Thanks

From what I remember the inner ring has a groove in it to make a labyrinth seal. Part is around $40 new.