Hi,
Sorry for the delay in replying. I asked my mother as to whether her grandfather, Placido had any brothers. Although she is 90, she has a good memory. She is not aware of any brothers. The name that Placido used in Philadelphia, was Erato. I suspect the "I" was changed to an "E" to americanize it, as was done with my last name.
I wish I could have been of more help.
Good hunting, Sal Petinga