All parts for the UH-1H remain in production from a variety of sources, including Bell and a multitude of PMA providers. A UH-1H with composite main rotor blades, will outperform a Huey 2 at significantly less cost, and still utilize the original UH-1H drivetrain and rotor system. The airframe is simple to build, and can be done from the ground up using Bell approved fixtures, of which there are a significant number around, and you can order new ones anytime you would care to.
The T53 engine is still available new from Honeywell, and there are any number of configurations available. Comparing a UH-1H with a 412 is a little disingenuous, as the 412 is a poor performer in this role in any performance comparison with a contemporary upgraded UH-1H.
As for the dear old NH-90, just go and ask ANY of the Operators of this platform (if they have actually ever received them) just how it compares to the Bell, Sikorsky, Westland, Agusta, Leonardo, Aerospatiale, Eurocopter or Airbus platform it replaced.
Still a quite amazing development all the same!