Yes, it's an actual street in Bari, Italy, where both sides of my family hail from. During a visit a few years back I asked a cab driver who that person was, and he said MS was a 19th century statesman, though I've not really researched it further.
A friend from my gym spotted the street sign while visiting Bari recently and sent me the pic. So, to the right-wing caller Deborah -- who tried to imply that I've made up by name by screeching, sarcastically, "Did your mamma give you that name?" -- screw you!