Benzeenees,
Can you measure the bearing in mm? If you are in the US, you can get them from Smoothdrag, Boca Bearing, and a few others. You could also call Shimano and if it's your first time calling them, they may send it to you for free.
I was just looking at
http://alantani.com/index.php?topic=12.0 to see if Alan had noted the bearing size, and unfortuantely, I just cannot find it.
Bryan
Oh, and welcome. Glad you are able to join us.