I was very dissatisfied with the right hand mirrors offered for the older cars, pre '78, they left much to be desired when compared to the modern convex "fish-eye" mirrors.. ie " Caution Object Appear Larger"...
To solve this problem I looked through the fish-eye add-on mirrors offered for trucks.. I found a round fish-eye mirror that was the same size as the stock passenger side mirror on my '59 Ford F100.. I pealed the double stick tape off of the mirror, used clear silicone caulk/glue to attach the fish-eye over the original mirror... Worked perfectly..
I now use the same trick on all of the passenger side rear view mirrors.. I know the reflection is not perfect, however, I have learned that if I can see daylight between my car body/fender and an object on the right side, I have ample clearance...
The majority of '35 trough '40 cars all share the same problem when rear view mirrors are attached to the doors, left or right side, and especially the right, passenger side. The early bodies all "fatten out" from the cowl to the rear quarter panel. The Ford hinge pin mirrors do a good job of compensating for this body fattening, however, the long curved arms tend to look like they belong on a truck.. Actually the Ford trucks and cars shared the same type of hinge pin mirror..
The Volks Wagon hinge pin mirrors of the mid/late '60's worked very well on the '35/40 Fords..
I have the aftermarket "swan" type of rear view mirrors on my '39 conv. Not a Ford... I made brackets to fit where the wind wings originally bolted to the doors, added a convex 'fish-eye to the right mirror, rear visibility problem solved..