Also, could it be possible that since the inserts on PLB-1, 5, 25 and 100 are full (not split), that the PLB-500 is actually the backup chip (and the chips in rows 9, 10 and 11 are actually the issue) since it, too, has split inserts as does PLB-100a? Yet, the PLB-100a is in a group shot with the "full" insert chips... Could it be that all "split inserts" chips are actually the backups....?

JB