Do McCauley props fit?

It is rare that someone mentioned McCauley props.

Do the hubs and spinners fit a standard RV cowl or are they larger than the more commonly mentioned Hartzell?

Bill, you might just give whirlwind (ohio) a call. Their CS props use a "McCauley" hub, what ever that means. They have a machining center to make their hubs. A short discussion might get you what you want - prop flange, distance from flange to blade center etc. Best case is that you could use their backplate and spinner on a refurbished hub with blades of your choice.