When the painters were here, they pointed out that there were cracks in the extrior walls, mainly where the stone meets the trim.
For example, the window in the library out to the front porch, on the exterior, has these two huge beams vertically on each side of the window. There is a large gap between the beam and the stone work.
And there were other, minor, places where there were holes, along the fascia boards where they meet the stone.
For this long gap in the front, the main painter supervisor suggested a caulk that is colored to look like mortar.
That seems to work pretty well, although you do have to be very careful of where it goes -- it does not clean off well.I used just mortar (and water) on a couple of other places.