I have a Model B 12x30 with a D1-5 spindle nose and angular contact ball bearing spindle, which was bent when I acquired it.
I have it stripped down, and have straightened the spindle and bought a high precision Timken taper roller to replace the front New Departure bearing, whose raceway is greyed up presumably from running with a bent spindle.
(I priced replacement ND bearings, which were still available !!! but each bearing cost more than the $1500 I paid for the lathe)
I'm concentrating at present on rebuilding a smaller precision lathe so I can make some needed parts for the Pratt & Whitney.
The single tooth clutches are in a bad way, presumably from being engaged at too high a speed. I'm unsure whether to restore them or improve them. Much as I would like to do a loving restoration, I will realistically be using this mainly for hogging off metal, so I'm trying to keep my "better instincts" in check and focus on what I plan to build, rather than putting all my energies into tools.
As for the lathe, its beauty lies mnainly beneath the surface: many of the details are a delight, considering how long ago they were designed.