I don't know if the GMs had the "push to release" lever behind the key but it's worth looking into. I can always draw out the wiring adapter diagram if somebody wants to cut the ends off of an old turn signal and ignition switch to splice onto the columns wiring.
The auction also listed these models that have the same column if you want to search ebay, craigslist or junk yards.
CHARGER 77-78 Floor Shift; w/tilt wheel
CORDOBA 77-79 Floor Shift; w/tilt wheel
DODGE PASS. 77-78 Floor Shift; w/tilt wheel
MAGNUM 78-79 Floor Shift; w/tilt wheel
PLYMOUTH PASS. 77-78 Floor Shift; w/tilt wheel
Hollander Interchange #: 238-845
158385