Doug,
I sooooo know what you mean. I love the knock-knock-knock sound of the BAR and I would love to own one. I do know that at one time there "were" part kits with cut receivers, but every place I have contacted has said no more. I really hate to break it to you, but unless you want to send the 10K for a real one, Ohio Ordnance is the way to go. That is unless you find some little old lady selling off her dead husbands collection.
If I do find a kit or a lead into one, I will let you know.