The fare rules state:
Category 15: Sales restrictions
TICKETS MUST BE ISSUED ON/AFTER 20MAY 17 AND ON/BEFORE 22MAY 17.
So dont hang around if you are keen!
I managed to price up the route by
Misco60 above on ITA Matrix for £1280, but clicking through to AA.com gives $1960 - anyone got any bright ideas about how to get it for the Matrix price?!