Cool bat! I was clueless on this and wondered if this was Clemente's brother or something? But did some research and found:
http://www.post-gazette.com/sports/p...s/201208030220
"Momen Clemente was his nickname as a child," Mr. Scheier said. "Apparently, when he was a child, he was often deep in thought and when someone would call him, he would say 'Momentito,' which meant 'Hold on a second.' And that was how he got that nickname."
Clemente didn't start having his bats stamped "Roberto Clemente" until the 1961 season.
"This is one of the final 'Momen Clemente' bats, which do carry a premium," Mr. Scheier said.