Hi Mike,
well now the discussion gets an interesting turn 
, as I do usually implement an (abstract) (cross-application) database layer ... for caching, performance and code-organization's reasons,
... but I never thought about to use this for faking database access in order to (re-)generate test data. If I understand the concept right, you would had encapsulated the database access and switched on the document number, e.g. TC_0001 instead of 4500000123 to return static test data instead of the real document from the database? If so... I do like the idea, ...
... so I'm eager to get a chance on an upcoming integration test to use some smaller Unit tests to get some experience ...
Thx for this valuable input and remarks and ...
take care
Florin