get some sheet metal and a cheep bender from harbor freight and build a set up that bolts in where the sluice flair bolts and add a hinged bracket..

wish I could draw it out for you on here.

if you build a box for your basket and add a brace/bracket off the top on one side with a hinge mounted to the flair of your sluice so it can be flipped to clear out rocks. you can even build the box the same shape of your sluice to maximize rock cleaning area..