Now, that is secure. I also found that Microsoft still has the tabs available for purchase. I bought the newer keyboard and also the new pen/tip kit for my Pro 3 and the new pen fits into the tab perfectly as well. The new pen, by the way, works a lot better than the original and you can still keep the old pen paired to the tablet as well (have both for use).
The tip kit, however, has no way for storage but does have a built in clamp to change the tips with.