Originally Posted by
midlevels
This is what the missing mileage claim page has to say about your scenario:
Before making your request please note:
Your request must be made within 6 months of your original flight. For new members, only flights taken less than 1 month before the member's enrolment date will be accepted#.
#Club miles and Club sectors cannot be claimed for flights taken before enrolment in The Marco Polo Club.
Unless you can find a way to join MPC before your flights I think you might be out of luck.
Although this is the rule, MPC has the discretion of counting some recent AMs posted before the joining date for early promotion to SL. My nephew got MPC GR via his CX-Amex card, and became SL after a few flights. That was probably because MPC also considered his flights prior to joining. That was several years ago though.