voltage regulator

I am looking for a voltage regulator that is compatible for a 1999 New Holland TC 18 tractor. NH wants $330 for the regulator. Is there something compatible for less. I have seen in other forms a J5050 from EBAY motors. Any help would be greatly appreciated

I have a stand-alone 6KW generator powered by a Yanmar engine model L100V6EA1C1AA (Engine Number: M29254). It has worked fine since 2013, but now the 15-amp fuse between the battery and the ignition switch and regulator blows instantly when the key is turned to Ignition. I traced-out the wiring...