A Craftsman style house is very different from a ranch. For me, Craftsman style is all about the layers and angles of a complex roof and front porches with beefy tapered columns. You mentioned an L-shaped courtyard, but are you planning to build up and significantly change the roof line?

ETA: if not building up, the one obvious change is to add a Craftsman-influenced front porch and change the windows to something more appropriate. There is a ranch near here that is currently undergoing those changes, along with adding a partial stone face, which you already have. Those changes are definitely giving that house an A&C vibe.