Steve, is the latch the shiny rectangle in the bottom-center? Or is that just the release for the GG hood? The latch and springs sound like quite an improvement over the basic Maximar slide-off system so many plate cameras used. Using my 9x12cm plate cameras I've run into occasional light leaks from the felt light trip, but I think the springs on yours might lessen the chance of that problem. Great if they'll accomodate several of the other variant 9x12cm holders.