Having spent some time searching the S&W User’s Group and not finding much information, I was hoping someone could answer my question. I have a 4 inch 586 round butt, 586-3, S/N BD N8202, that has a mat blue finish that I would like to know the year of manufacture? I purchased it with what I believe is an Ahrend’s RB grip. Can anyone please provide additional information on this S&W revolver? Thank you so much.