That said-- but under circumstances of no relevance to the case at hand-- BA.com most definitely -will- sell AA operated, AA #'d flights-- I know because I bought one there very recently (AA101). But, again, under circumstances not relevant to determining what's going on with the OP's situation.[/QUOTE]

I'd be interested to learn how to accomplish this. If you are able to in fact purchase an AA #'d flight on a BA itinerary, you could conceivably use dual instruments to upgrade?

As in booking a reduced fare WT+ ticket and upgrading to CW with 10k Avios outbound. Then if the return flight were AA metal with AA # you could upgrade with SWU or miles/co-pay. This is at least what has been conveyed to me from AAdvantage agents. The AA flight # on these itineraries is key. I just have never been able to execute without a codeshare #'d flight.

It would be a nice option for those with AA miles and Avios wishing to upgrade.