Detroit locker

Those are casting numbers for parts identification and not anything to do with a model number. The hand stamped numbers are for inventory control after it was produced.

You'll not hear anything back from Eaton on this request.

Having drilled bolt heads holding the halves together tells you someone seriously raced it in the past.

You basically have to know what you're looking at with any differential. Post some wider angle photos and I can tell you more about it.

Tom