Unless that bank acct. from when you were 5 is somehow being reported...you shouldn't have a 25 years old credit file. Your credit file actually starts with a line of credit extended to you. Were you possibly an AU on gpa's acct at 5? From what I understand...our 800+ FICO friends have credit histories that date 30 years or so! Everyone on here is right...unless it is ONLY a personal thing...any thing above 780 isn't treated any differently than a perfect 840!!
$1,000,000 in mtg's might have an impact on why your scores are stuck?!...What was the original balance of those mtg's They may be reporting 90+ % util....same as auto.
Your credit is excellent...and something you should be VERY proud of
Lowering any util. will be where you can possibly see an increase. YMMV That and aging of your file, you are on the right path, though!
takin' it one day at a time