Well, in fact the real Italian name is Colombo, not Columbo. To me, it doesn't seem enough to americanize the name, but maybe just one letter makes it sound less foreign .

I know that one of my uncles was named Onofrio.......How freakin guinea is that????? but we always called him Uncle Al...or Uncle Ally....I have no idea why.....we are a strange family!!
I also had another uncle named Nebo....what is up with that???