Complex sentence: The West Church congregation was dissolved in 1961 whilst in 1980, the East Church and Loudoun Church congregations amalgamated, leaving Loudoun Church the main place of worship in Newmilns.
Split into simpler sentences: The West Church congregation was dissolved in 1961. The East Church and Loudoun Church congregations amalgamated in 1980, and Loudoun Church is now the main place of worship in Newmilns.