You do realise that in 1969 DVLA did not exsist?

It is possible that you have 2 records, this is not unheard of. If you mislaid a licence and then applied for a new one with a slight difference in the details (e.g. a second initial on one of the applications) you would show up on the system as someone else, thereby creating two distinct records. Were there any spelling mistakes on your licence? Was the date of birth correct? any of these things can change your driver number. Worth thinking about.

As I work in DVLA, I can help. It is only the photograph that expires, your driving entitlement is NOT affected at all.