Marylyn- You can request all 4 weeks for the 4th of July week- BUT- keep in mind that you would only be able to call at the 13 month mark in that case, not at the 13 month + 3 week mark as suggested by dioxide. You could call at the 13 month mark, though, and reserve all 4 weeks.
Alternately, you could consider reserving the week before the 4th for one of the weeks, which would let you call at the 13 month + 1 week mark, reserving on Manor Club week for then and, at the same time, reserving the other 3 weeks for the 4th, which would enable you to secure 3 holiday weeks. If you really wanted, at the 12 month mark you could call back and try to change the week before for the holiday week, for a $29 change of reservation fee.
Make sure to get separate reservation numbers, of course.
I just remembered something, though- isn't the week of the 4th sold a a Plat. Plus week at NCV? I thought I remembered reading about that in another thread, in which case you couldn't book it. I'm not sure about that, though, so others will have to chime in.