Your question is post in the wrong place. Should be on the Model A forum.
Not sure what your goal is.
If you drive the car at all having an outside mirror is a safety item and may be required by law.
The A came with an inside mirror from the factory mounted over the windshield on the header about at center of same.
There were some different versions of outside mirrors over the years but the door hinge mount is the most common of what you see today.
Photos and a description of what you are planning would help.