I think the wildcard in this is the recent D check - that's a good chunk of time and money (plus it may have also included interior upgrades if the plan was to keep the airplane in service for several more years). Basically, if it'll cost less to fix it than to D check a different 'soon to be retired' 747, then it probably makes sense to fix it. And it shouldn't cost much for most of the necessary parts to repair it - just rob them off a recently retired airplane.
I'm just surprised at how long it's apparently taking to make a decision.
