Tom, just looked at my PB Garand after reading your post. It is one of the BMR/PB receivers. How neat!
To the OP, I found mine at the Lousiville, KY National Gun Day Show about a year ago now. There is a Breda M1 for sale on gunbroker.com right now, but thats usually the extent of their availability. As someone else said, they show up when you don't expect it. When I got mine, I had never seen a Beretta M1 before and was surprised upon encountering on in person. Its another neat addition to the collection. Good luck.