This is/was BH9197 (haven't been on in a long time and my old ID is tied to a now non existent email account)

Yes. everyone should hang on to all Tickets, Boarding Passes, until you see those miles posted. I have done this even before the "merger" started.

On my original US booked, AA metal flight that got cancelled, I had 2 different Record Locators with a US (037..) ticket number. When the AA flight cancelled and got rebooked on US metal, I then had an AA (001..) ticket number, and new Record locator.

Without the hard copies I never would have any miles re-applied.

Another problem I found out from the reps I dealt with is that the Record Locators on U.S. contain digit(s), while AA Record Locators do not (its all characters). I'm an IT guy and I'm guessing this is probably a really big technical hurdle during the merger process.

My heart goes out to the employees that have to move to/from DFW-PHX-CLT-PHL-....... during the transition.