Complex sentence: Because of declining members of the convent and the school division no longer renting classes, the building went on sale in 1983 only to be bought by the town on March 27,1985 to be the Museum of Willow Bunch.
Split into simpler sentences: Because of declining members of the convent and the school division no longer renting classroom space, the building went up for sale in 1983. It was to be bought by the town on March 27,1985 to be the Museum of Willow Bunch.