The only markings that I can see on it is the stamping '9L10'... other than that, I don't know anything about it... a google search on 9L10 didn't really come up with anything useful...
It was tight on the spindle, but wasn't turning... I could spin the spindle by useing the chuck for leverage, but it looked like the spindle was slipping in the bearing race. I could be wrong...
When I got the spindle out, I looked at it closely, and it didn't show any signs of wear or galling, so the bearing may have been turning. I could not turn it with my hand until I soaked it in oil for a while.
It fits on the spindle and in the headstock bore like it belongs there, so I feel like it is the original bearing.