First, would either of you gentlemen like to come cook at my house? My idea of the dernier cri in kitchenware is a ginger grater shaped like a flounder (I love it).
Second, I remember an anecdote in one of my cookbooks about noodles being rolled on a guitar body and cut through the strings. I'll bet whoever did that heard the old "shaving your legs with my razor again" lecture! So maybe someone cut an egg through mandolin strings and dropped it into the belly? That could account for the name, and for that fancy rose on the sound hole in the mandolin!