Track down a bunch of places in the 'inventory' code that was passing simple tuples into the CHKMap layer. Note that almost all of these are cases where we started with a file_id and then want to translate that into the CHKMap lookup key. As such, these aren't places where we would expect to already have a tuple. Since the Inventory api is in raw strings and not keys. Anyway, forward progress as this fixes a lot of failures.