Was Mozart famous for rewriting violin and cello pieces into viola pieces?

No, Mozart was not specifically known for rewriting violin and cello pieces into viola pieces. While he composed a number of works for the viola, including concertos and chamber music, his contributions to the viola repertoire were original compositions rather than adaptations of existing violin or cello works. Mozart's fame primarily stems from his prolific output across various genres, including symphonies, operas, and chamber music, rather than for reworking pieces for different instruments.