Here I come along three years after the fact and the posting by Alaska Steve appears to be absolutely correct! Great research! According an e-mail that I just received from a Cherry representative, part 519-004-0 is obsolete and the closest they still make is the E-13-00E which has the extra (marked NC) terminal on one end. Allied Electronics stocks them for $3.06.
My best advice to get the two halves of the weatherproof housing separated is to gently secure one half in a vise and (I used broad jawed channel lock style pliers) gently pry the other half away - some rocking is required and you'll hear the plastic pins inside breaking off. Just make sure not to break the housing in order to maintain a water-tight integrity following the repair. You can re-secure the two halves without much difficulty as there is a gasket between them, and the mounting screws that hold the assembly to the engine should keep them held tightly together. And you can always use some silicone, too.
Thank you!
