Until I see a number of pictures, the reporting of Singer made Garands and Carbines is about as verifiable as Elvis sightings. Or, weapons of mass destruction in Iraqi.
(We went to war with less evidence than whether Singer made carbines!)
In so far as the question whether if Singer makes the receiver, does that make the carbine a "Singer"?, that is a philosophical and legalistic argument. No grocery store owns a cat food or vegetable canning factory, and yet I go to the store each week and see "store brands". A friend of mine worked on an oil can line, he said from the same 30,000 gallon tank of 10W-30 oil, he filled tins that were labeled with every brand of oil in America, except Penzoil. So, in the case of grocery stores and oil cans, who is considered the "maker" in terms of liability?
In terms of contracting, the Government holds the prime contractor responsible for the product. Singer could have made 99.99% of the parts in M1 carbines, but if "Oscar" is rolled stamped on the receiver, and "Oscar" is the prime, "Oscar" is the manufacturer and is the one who is legally responsible for all aspects of their carbine production.
