Super bummed. New motor. Bad bearings?

I am thinking that tight clearances would have wiped the bearings and the crank journals, moving metal from one to the other. I did not see that.
What I did see on the bearing shells was evidence of debris passing across the bearing faces.
As been said many times. Machine shop hot tanks are really effective in removing external grime and sludge. They are just as effective at depositing that grime and sludge in the block-head-crank interior oil passages. Hot water, dawn dish soap and the right sized bottle brushes are not only your friend here, they are your lifeline.