Looking for a source !

Does anyone know where I can get the 3 prong female plug that goes on the backup/neutral start switch on the 727 tranny for my 68 barracuda ? I've tried running wires to it , but they won't stay connected (bayonet connector). I remember someone else asking this question a couple of years ago, and the search came up empty. Any Ideas ????????

Jon Rutka in Deerfield Mass
1968 340 S
2006 300 hemi C