1940's welterweight Billy White from Baltimore has two fights on the same day, April 30 1943.
Plus in a Ring Magazine (May 1989) segment about Johnny Cesario. it says:
"John likes to tell of his 1st opponent Jerry Walsh and his 5th opponent Billy White. They were the same fighter using different names. Cesario won both by knockout"
I've added the Cesario comment to the Jerry Walsh fight. Does anyone think however this is enough info to change the name of Cesario's 1st opponent to Billy White? And give White an alias of Jerry Walsh?