A discussion involving the name Peres reminded me of this example of a non-Sephardic Peres family. I also first thought that Rabbi Jacob Joseph Peres of Memphis was a decendant of a dutch Sephardic family. But he wasn't... His father adopted the name in Haarlem in 1811. I have other examples of adoptions of Sephardic sounding names by Ashkenazim in Rotterdam.