Hmmm? I was thinking of pushing water up from the block drain and see if anything comes out from the opposite direction.
You could use a wet/dry vac and suction out from the wp hole.
Have you tried 'sort of' reassembling the broken pieces to get a sense of how much you're missing?
Upcoming NYC dates: Jan 8 and 27. See Facebook for other shows and PM me if you can make one...love to see you there!
Mangofy your E46!