Doug The Head,
I think you'll find most of the old -300's will be disappearing quite quickly, leaving the 'new' -300s (ordered direct from Boeing) and the -700s.
Suspect LTN unlikely as a 319 base as there are a lot of other more obvious candidate bases out there which will come first, bearing in mind LTN crews are all -700 and -300 rated, and LTN maintenance is set up for 737's.