Preparing an old stone foundation for stone veneer

I have a 200+ year old log house sitting on this stone foundation that has been patched and painted a bunch of times over the years and looks pretty sad. The stone itself is kind of a drab, red, flakey Pennsylvania stone that I don't think would clean up too well even if I managed to remove the paint, chip out all the old mortar and repoint it. So I'm looking to clean it up and apply stone veneer over it.

The part of this that is puzzling me is how best to deal with the very un-even and...

Preparing an old stone foundation for stone veneer