Good Job!
Looks like a longer down ramp than I use and it should work just fine

Always was a woodworker myself but aluminum is so easy to work with I have used it for many projects in the last few years and still going.
Right now I'm building a gold and gem fluid bed sluice for a 5" dredge to be installed in a pontoon boat.
(completely original design)
* Very Important I just noticed that you have not installed the diverter baffle. It is a very important part of the design to increase efficiency and reduce gold loss!
Attach a piece of aluminum at a 45 degree angle just after the trap intake port and make sure it extends downward 1/2" below the height of the overflow port. That way any gold entering the trap will be diverted down into the trap and not be allowed to just surf straight across and over the discharge port.
<img src="http://www.treasurenet.com/forums/attachment.php?attachmentid=741177"/> <img src="http://www.treasurenet.com/forums/attachment.php?attachmentid=741181"/>
GG~