Gas cap/shifter mods

Has anyone put a flip style gas cap on a duster?(challenger charger early barracuda style?)
If so were any mods to the quarter involved?

I,m also consdering mounting an aftermarket shifter in a factory console(b M Quicksilver)
Or converting to a factory "SlapStick?

Any of this sound farmiliar to anyone? I'm not afraid to forge ahead on my own but no need to "re-invent the wheel" if somone has been there before me!!!