Hello Michael,
You could try Just Bearings [look them up on Google] who sell a comprehensive range of bearings, oil seals and other such useful stuff, or take the extracted parts to your local bearing agent and see if they can match them.
I don't know the drill model at all so can't offer advice on how to take it to pieces
I would suggest too, once you have daylight on it, you look at the condition of the fibre gear. The untimely release of drive under load which started this thread could have damaged the teeth and that too may need replacing. PM me for help with that.
Regards Brian