I've never done any historically significant homes, so I am obviously shooting from the hip... but modern stone would look out of place here I think. I've stacked some natural stone walls, and given the architecture and period of the house, I would push hard for something that would be more period appropriate, less modern, more rustic.
From what I've seen of you work, I know whatever you do will look great in the end, but modern stacked stone walls do little for me here. That color isn't right, and even if you go with modern stone, there are choices that would look more rustic than what you used in this concept.
The stepping stones in that one pic you posted (the one that appears to block the walkway) was functional.... get off the horse and onto a raised platform that would then lead to a walkway to the house, with a nearby post for hitching the horse. Those big stone blocks work fine for that, but a raised paver/block platform just doesn't fit.
Sure wish I had a few jobs like this one I could play with design-wise... good luck!