Thanks all!
Since I have all same cells (year, chemistry, everything). I will make up an extra pack. What complicates my situation is, my packs have a "handiness" to them. That is, every other pack had buss bar that exits the packs differently (one in the front the other in the back). But I will make and extra one, and just have to undo the welding if I want to swap it out. Unfortunately, I don't have enough cells of the capacity I want to make 16 packs.
On second thought, I think I will take the 10 cells and just discharge them to about 3.6 V for storage, and not put together the spare pack until needed. In fact, I can use my two MegaCell Charger to discharge the cells!! Perfect, I want to try it out and this will give me the opportunity to use it and get familiar.