1967 Barracuda Fast back Mirrors

I have a question regarding exterior mirrors on my 1967 Barracuda. I do not have a mirror on the passenger side , but , my door has holes for one . I have looked on line and all 1967s I have looked at do not have a mirror on this side.
Is this a preference thing ? Does anyone know where you might locate an exterior mirror or steer me in the right direction? Thanks...:prayer::newb: