Allie- great family history!
I wish I could help you with the question re: the Sigma Nu pin. I know when you get "pinned" you wear the fraternity pin next to yours on formal occassions. Maybe you could post your question on the Sigma Nu board and see what they say. I had a ring made out of my grandmothers pin - ?? If you wanted to make something that you could wear everyday or you might just want to keep it- who knows- 30 years from now you might have a son who pledges Sigma Nu!