I saved the spreadsheet in CSV format, sorted by netname, slot, pin, and compartment. I then whipped up a Python program to look for successive entries that were duplicates in those fields. This gave me a hit list to use to strip the excess entries from the database. At the end of that process I was down to 6,900 entries.
I then ran a different sort, using only slot, pin and compartment, to look for duplicates that might have different netnames. This would flag any entries where the netnames differed or entries that might erroneously assigned. I discovered 80 duplicates by this method but resolution will be slow.
I will need to look directly into the relevant ALD pages to find what the correct values should be. This will occur over the next day.