What is perhaps the coolest thing about this pin is that it comes from the home of the family who created McDonnell Aviation in St Louis. I purchased it along with an ABA Executive Council pin from 1942-45 which is inscribed to ?W.A. McDonnell? with ?ARK? below on back. William Archie McDonnell was the brother of John Smith McDonnell, founder of the McDonnell Aviation, later McDonnell-Douglas and now Boeing. He was born in 1894 and assuming he went to law school in his early twenties would date this pin to 1915-1920. ABA pin is not yet up for sale but will be soon! Phi Delta Phi pin weighs 1.3g and has been scratch tested for 14K. The provenance is worth so much more! Condition is Used. Will ship USPS with tracking to winning buyer.