Well, whatever the heck a "74W" is, it looks like LAX gains it on 29/5 and then looses it again to YVR on 18/8 for another "B777-300". 17/8 YVR looses it's "B747-400" and gains (presumably) LAX's "74W" on 22/8.

jimbo99's guess at seating sounds about right to me but this "74W" is still selling F C ED and Y.