Drive sleeve play?

[lefty]

Hi everyone - i inherited a first generation "greenie" from my grandfather and have begun to use the lather on a fairly regular basis.
I have begun to notice that the pen mandrel seems to be developing a run-out/wobble that has gotten worse over time. I know I should expect some play but it has definitely fallen out of tolerance.
I removed the quill to inspect the single bearing and it seems to be in shockingly good shape. My question is; can the drive sleeve cause wobble? If not I don't want to go through the hassle of tearing the headstock down again if this isn't the likely culprit. Or is it possible the quill bearing may be in fact worn out but just look/feel fine in my hand?
Any help is greatly appreciated!

todd

[JPG]

Which end on the mandrel are you observing the runout?

[jsburger]

Which end on the mandrel are you observing the runout?

Also, does not a pen mandrel require a live center on the right end since it is very thin?