Here's how I did the west coast mirrors on Bruiser. Truck originally had the swing away sport mirrors and I reused the brackets that bolt to the door.
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Passenger side with a convex mirror clamped on.
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I mounted then with one short arm and 2 long arms each. Plan to eventually put a stud in the factory nut with a wingnut so the mirrors can still be folded for trail rides.
I really want to get the equipment to powdercoat stuff myself and do the arms and mirror backings to match the rest of the hardware. You can see where the flat black spray paint has worn off after a few years.