The best defense is a good offense, and this is a good place for one, since the edicts in question can easily be shown to be illegal infringements and not the reasonable restrictions they are claimed to be. Always better to take the initiative instead of just trying to keep your enemy from taking more ground.
I'd think the minimum o/a and barrel length would be the easiest to do away with, especially considering the excuse given by the Court for its decision. Compact shoulder-fired weapons definitely do have a place in the arsenal of the militia, whether the Court wants to see it or not.
Legalizing machineguns does not seem likely no matter who controls Congress and the Executive. But I think the definition could be made more realistic. An automatic rifle, for example, is not a machinegun, and neither is a sub machinegun, at least insofar as being designed to mow people down, which seems to be the reason for the law against them being called reasonable. So I would suggest that the definition of machinegun for the purpose of law be changed from more than one shot being fired with a single trigger pull to more than three, which would allow tri-burst. That plus no minimum length would put small arms of the militia more in line with the 21st Century. Devices that allow bursts to be fired legally have been available for a long time, and I'm not aware of crowds of people being mowed down by guns fitted with them. If anyone knows of such a thing, or if they've been a significant problem for law enforcement, I'd be interested in seeing information on it. Otherwise, if they haven't been a problem, a case can be made that tri-burst would not be a problem either. If it was up to me full auto would be legal, though if it was my rifles would be capable of single shot or tri-burst; I'm not interested in full auto. Those who are should be able to have it, but tri-burst would be a good compromise with anti-gun bigots.
Also, violations of NFA edicts should be treated like speeding tickets. For example, if a person has a rifle that fires full auto instead of semi or tri-burst, give him a small fine and tell him to change it; this makes more sense than throwing him in jail. What leads to more death: the difference between full and semi auto, or people driving too fast? And there isn't even a Constitutional right to drive.
Silencers being legalized seems unlikely because many people believe that the sound of a gunshot will bring police, so without that sound there would be more murders. I don't buy that reasoning, but a lot of people do. I'd still like to see them legalized, because they could be invaluable to the militia.
Another adjustment that could improve the NFA would be to say that a concealed carry permit automatically makes the bearer able to legally possess class III weapons. We've been fingerprinted and investigated and tested, and we have earned a reputation of being very law-abiding and competent, so you'd think this could pass.
None of this will happen though as long as the liars of the liberal press continue to have the amount of control they now have over our political system. So fighting back against their big lie campaigns and exposing them for the propagandists they are is the critical path to getting things like this done. Toward that end I mention on a regular basis to my representatives that I'd like to see them stand up to the liars of the liberal press. And when someone does stand up to them and is subjected to one of their hate campaigns, I do my best to support them in their battle with those traitors. If all patriots would do this, we might end up getting some more realistic laws.