From what I understand, the shell of the nx2000 and nx1600 or whatever it is you have are identical, it's just the engine and options that are different. Therefore, it's core support should work fine. Since you already have it there, I would suggest that once you find a person to weld it in, to let them remove the good one so that they can get it out exactly how they want it.
No clue on the price, but as always, contact Tinman or Desperado to do the work for you.