I have recently been added as an AU for an AMEX card that has been in good standing since 1989. I also was approved for an AMEX DSM card this month. My question is twofold. Will my AMEX DSM show that I've been a member since 1989 (the only reason i asked to become an AU was to try and get the history)? Secondly, if the history is added, what would happen if (later down the road) I was removed as an AU on the aged AMEX? Would the history remain on my personal AMEX?
Your card will be 2008, the auth account will show on your credit since 1989, but when you open cards in your name it will put the oldest age of accounts in your name, which if this is your first amex (2008)
if you remove yourself later, it either will just show closed and keep the age, or they possibly might delete the whole account from your credit.