Tenure at bank not reflected in my Credit Score

So I opened a savings account when I was about 11, and now I'm 35. The original account was cosigned with my mom, and sometime in my 20s I switched it to a solo account at the same bank. My credit score, though good, says that the relatively new age of my account it part of the issue. Is there a way to retroactively benefit from my first account? The banker never mentioned any reason for me to keep the first account going for credit history (this was around the time when Wells Fargo bankers were getting bonuses for new accounts they opened or whatever also). I'd love to benefit from having a long standing account with the bank, but not sure how to go about it. Thoughts?