I ended up doing a bit more than I originally bargained for today...
I went ahead and took the motor out of my L-34, separated the top and bottom halves, cleaned out some gunk from within the motor, and then decided I might as well complete the process while I'm in here. I used a 7/64" bit to drill out the rivets, used acetone to clean the oil pads, baked the brass bearings in oil in a 150 F oven for 1 hour, and then reassembled the motor and turntable. I did a bit of cleaning on other parts, but figured I would go back when I get the new motor mounts that I decided I need. Overall it went well, but 2 points to remember when you reassemble the tables: the motor doesn't have directionality except in relation to the table. I kept the label in the same place, but failed to install the grounded rod at the back of the motor when I reassembled it - so I had to take everything apart again to move it. I also didn't screw the button at the front far enough into the table, which again meant removing the motor from it's mount to tighten it a bit.
I need to get to sleep so I only played part of a song - it now gets up to speed almost instantly (rather than taking 2-3 minutes). It may have been a touch quieter, but it was tough to tell. I'll put in a long session this week and report back about the rumble. I also took some pictures that I'll post for anyone that plans to do this.