I have the PSI 'TSGUARD' overarm dust collection guard which has served me quite well. This system can be had from several sources for just under $200. The system includes the manual, adjustable vertical mast with stabilizing rods, the adjustable horizontal arm, hood, hood-hose, 4" adapter cuff, etc.
The hood has a small damaged area as shown here:
However, I also have a brand new hood and arm mechanism (no counterbalance weight) along with the short pipe for ceiling mounting a-la Bill Arnold.
Shipping would probably kill the deal but, I will sell it all to a Family Member for $100. If you are an hour or so away, we could talk about meeting half way for delivery but, let's remember that gas is about even with gold per ounce .