Possible Clues:

• Topo ___ (sparkling mineral water)
• Topo ___ (Mexican mineral water)
• Oldest of the Marx Brothers
• Young ''hombre''
• Home to a California State University campus
• The eldest of the Marx brothers
• Pianist of the Marx Brothers
• Piano-playing Marx
• With 35-Across, actor who said 'You can't fool me, there ain't no Sanity Clause'
• Marx brother at a piano