I'm sure to have one of them, but I'm not sure where it is ;-) so I decided to DIM (do it myself!) an N3 plug.
Step 1: The reference
Step 2: The pins guides
Bend the wires so that they will remain in the mould after the casting, I've also glued them together with some double component epoxy glue.
To avoid that the plug sticks to the cast you can cover it with some silicone grease.