The old pins were made by the Balfour Company from Massachusetts.  Nice people.  But they got bought up by a conglomerate which promptly went belly up and took Balfour's with them.  The old patterns and dies disappeared in the process.  The National Officers went looking for a new national jeweler and got some horrifying cost estimates from the other fraternity jewelers - so they went for the cloisonne "blue moon" pin to keep from more than doubling the pin cost.

More recently some chapters have been dickering with local jewelers who have been suggesting the old style pins can be made for less than an arm, a leg and a first born child, but I have yet to hear if anyone's gone forward with the idea.