There is an interesting annotation to the 28-1202. Carrying concealed weapon; penalty; affirmative defense.
When a person is charged with violation of this section, the State need not prove that a revolver or gun is operable in order to establish that it is a "firearm". The test is whether evidence of possession of a revolver or gun of prohibited description, which is in apparently good condition and has the characteristics and appearance commonly understood to be those of the firearm it purports to be, is prima facie evidence sufficient to go to the trier of fact in a prosecution for carrying a concealed weapon. In re Interest of Cory P., 7 Neb. App. 397, 584 N.W.2d 820 (1998).
So as stupid as this sounds, but kids do stupid things. A kid who carries some form of a replica gun to look 'cool', could be charged with a concealed carry and it is up to the prosector wether or not it is a felony or a misdemeanor?