Are there left and right mirrors. I have a '71 that didn't come with passenger door mirror but I'd like to put one on?

• What is the dimensions of the mirror itself (height by length? Thanks. fitment
• I am missing a inside nut or sleeve the screw goes in on door , do you have a couple to replace them? general
• What is the distance between the screws on the mirrors trying to determine if I will be able use existing hole(s) and/or general