What is the proper way to patch an old home's stone foundation?

if there are no structural problems, it's a matterof repositioning the stones. You;ll need a good bonding epoxy based concrete mix. wet the existing surface, it makes for a better bond, and fill in the small spaces well before placing the stones. If it has gotten bad, I would recommend calling a mason to come out. Just don't let them use regular Type S mortar mix. It's not that strong.

loan forgiveness