I have no idea if it works in this particular case, but you could try manage my booking at QR. QR can select seats on regular AY flights even when AY can't themselves.
Originally Posted by
nivsy
...
Also another swipe at JL, (not really for the AY forum) but amazingly I am booked J Class on a JL flight between Tokyo and Osaka and even now they cannot allocate a seat for me in the J cabin as they "dont do this for domestics until 2 months prior to departure"...what a nonsense!
That is the Japanese way.