Is there a Byte-By-Byte Duplicate File Removal app for Mac? (not SHA-1 or MD5 hash!)
You could do worse than to try dupeGuru, available from Hardcoded Software, I've had very good results with it. It presents numerous options for fine-tuning your search and will perform byte-checking comparisons.

In addition to the standard dupeGuru there is a music edition as well as a picture edition for more specific media searches. It's free so give it a go with some test files and see what mileage you get.