OK guys I know I am thread crashing but I had to see if anyone has the answer to this question. I recently came across a Sigma Nu pledge pin and it did not have the normal vintage screwback or the newer style of a push pin, instead it had the clasp type back. I have seen many pledge pins offered, but never have I seen one quite like this, I was wondering if anyone could possibly date it, or inform me if it was a rare specimen. I tried contacting the Sigma Nu HQ about it because my usual informant on fraternal jewelry really didnt have a solid answer either. If anyone can provide me with some insight to this pledge pin I would greatly appreciate it.