I am trying to learn how to VAM. After reading more about VAMming I bought macro lens for my cellphone so I can take better close up pictures especially from date and mint mark. Unfortunately this coin is already in local auction so I can't take better pictures.
My other option was VAM-13 but I think mint mark resables more VAM-21A. Anyways back to taking pictures from my other Morgan dollars and trying to VAM those.
You are correct with the VAM 21A attibution. When I enlarge the reverse photo I can distinctly make out the die scratch in the 'O' mintmark. Clashed dies are the easiest attributions for me. The neck clash line from the eagle's right wing (viewer's left) and the wing clash line in Liberty's neck are in the exact same location on every coin from those dies ... the closest thing to fingerprints.