Complex sentence: In 1942, a great majority of his works were auctioned off and most were purchased by the "Fundación IWO" (the Argentine branch of YIVO) and were stored at the Asociación Mutual Israelita Argentina.
Split into simpler sentences: In 1942, a great majority of his works were auctioned off. Most were purchased by the "Fundación IWO" (the Argentine branch of YIVO) and were stored at the Asociación Mutual Israelita Argentina.