Who is Buck Leeper from Out to Canaan and what is their importance?

Buck Leeper is a construction supervisor who has come to Mitford to watch over the renovation of the Lord's Chapel attic to make more space for Sunday school classes. Buck Leeper is a recurrent character, having been in a previous novel of the series when he came to help with construction at Hope House. Buck is an alcoholic. Father Tim attempted to help Buck previously and was successful enough to help Buck reach a point where he only drinks on the weekends. However, Buck refuses to acknowledge he has a problem until he loses Pauline Barlowe after encouraging her back into the bottle. Buck returns to Father Tim and asks for help, which Father Tim willingly offers.