TT, there are two possibilities here:
1) Your credit file is in a shambles, is a complete mess.
2) FICO Reason Codes are drawn from a Magic 8 Ball until perfected, and thus cannot be managed, should not be worried about once one reaches 800.
Who thinks #2 ?
NRB525, I figured it out - I'm being scammed by the CRAs! 
The CRAs keep dropping off older payment records on my open accounts. Only the latest 7 years of payment info shows on each account. Prior history - gone. Now I see how they can get away with "short credit history" and "you have not established a long credit history". 
Without the associated payment history the value of old accounts is diminished.
Which banks are your accounts with? Seems odd one persons file or certain files are handled differently than others.
NRB525 - I'm sure my accounts are handled no differently than anyone else's. My above post was a bit in jest - no real epiphany nor shock nor frustration on my part.
The drop in credit history I was referring to is payment information displayed on CRA reports. Pasted below are examples of what I see on a CRA report. On CRA reports - payment history on the reports is truncated nominally at 6 to 7 years. Thus, the above jest.
Dates for each account opening are listed correctly so AAoA and AoOA are undoubtedly calculated correctly by Fico. I took the opportunity to play on the truncation as a justification for getting the "short credit history" reason statement although AoOA is 34 years, AAoA is 18 years and AoYA is 6 years.
I realize it would be impractical to list monthly details on all accounts back to time account was opened.
