Actually they can :take judicial notice" of any well known fact. Bottom line, Miller and Layton were the day's equivalent of gang bangers, a bit long in the tooth gang bangers by today's standards. The court did not want them to get off "scot free". But anyone who reads the courts decision can see that it's about 99% dicta, a whole collection of irrelevant "Stuff" thrown at the court by the Justice department lawyers. (their brief posits many of the same arguments that the gun grabbers make today, all of htem rejected by the Court). The actual decision turns not on the second amendments actual language, but on the interpretation of a similar state constitution provision, one which includes "For the Common Defense", a provision specifically rejected by Congress when considering what became the second amendment. Thus the version of the second amendment the court ruled on, was one which reads "the right of the people to keep and bear arms for the common defense shall not be infringed.", not the real second amendment.
The Court assumed that the second amendment is about the militia, but it's really about a right of the people. just like the rest of the first 9 amendments.
You can see all this in the following two paragraphs, which are the "meat" of the decision.
In the absence of any evidence tending to show that possession or use of a "shotgun having a barrel of less than eighteen inches in length" at this time has some reasonable relationship to the preservation or efficiency of a well regulated militia, we cannot say that the Second Amendment guarantees the right to keep and bear such an instrument. Certainly it is not within judicial notice that this weapon is any part of the ordinary military equipment or that its use could contribute to the common defense. Aymette v. State, 2 Humphreys (Tenn.) 154, 158.
The Constitution as originally adopted granted to the Congress power - "To provide for calling forth the Militia to execute the Laws of the Union, suppress Insurrections and repel Invasions; To provide for organizing, arming, and disciplining, the Militia, and for governing such Part of them as may be employed in the Service of the United States, reserving to the States respectively, the Appointment of the Officers, and the Authority of training the Militia according to the discipline prescribed by Congress." With obvious purpose to assure the continuation and render possible the effectiveness of such forces the declaration and guarantee of the Second Amendment were made. It must be interpreted and applied with that end in view.
You are right. I read more this afternoon. The justice dep spent pages talking about how things were in England to justify their position. Isn't that precisely why the FF insisted on the 2A?