Hi Bryanb,
Welcome to the forum hope you find heaps of info to help you in the hunt for the yellow stuff (or gems if that's on your agenda as well).
Just an initial observation in regards to your sluice .... may be wrong but I'm hoping some of our high banker/sluice experts will also comment but it looks as though the expended mesh is laid incorrectly ... rather than having it running up and down the sluice it should be laid across the sluice with the expanded sections high points facing to the back of the sluice, in that way the gold can drop into the 'hollow' created by the water flowing over them.
Photo is not too clear but not 100% sure about the welded riffles.
Try doing a search on sluices or high bankers and you should find a few examples that hopefully explain what I'm trying to say in pictures.
Great that you have access to a workshop ... you'll be able to churn out some great stuff.
Cheers Tom