The right to bear arms does not equal the right to carry concealed arms. Nor do I think that in colonial days that was ever the custom. Rifles and muskets were carried openly. Pistols were generally large and unwieldy and were usually either military weapons used by cavalrymen or officers (emblems of authority) or were used for dueling. Dueling pistols were transported in nice little cases, other pistols were carried in big holsters, often on horses, or inserted into a sash.
Thus the 2nd amendment, while clearly granting us the right to bear arms, does not clearly give us the right to carry concealed arms. Which was the point - I was not addressing the 2nd amendment since like you I don't see any compromise with it.
Actually, there is no specification or restriction in the second amendment as to how arms may be carried. Most restrictions come from activist courts "interpreting" the constitution.
I understood your point, but I don't see any compromise where one group (in this case the leftists who want someone else to buy them a train) would be giving up nothing while the other group (the red zone) would not only have to "register" to carry what they've always carried anyway, but they would also have the tax burden of building a train that they would likely never see, let alone ride.