Russ,
I don't know the part number for the seal, I'll check the shed to see if I have one on the shelf.
Just measure the shaft diameter, the housing diameter and thickness and see your friendly bearing bloke.
I used pop rivets to reassemble. I don't think that they will leak but if you are worried about leakage try to find blind rivets. Probably not worth the effort for three, though. A dab of silicon should do the trick.
Trev.