OK, I've been waiting for you to get back to me. I'll post what I've
got so far later on (in about 4 hours - have to do some work now).

By the way, any 6 digit date is ambiguous if it is xx19xx, as this
could be MMDDYY or MDYYYY - do you have any suggestions/preferences for
this?

I have assumed no leading zeroes, so if the first digit is greater than
1 then the date format must be MDxx_whatever, and if second digit is 0
(with first being 1), this must be MMxx_whatever with MM=10.

Pete