Sorry it's not a nicer picture but I took it with my phone while I was fishing. I forgot my camera.
Picture was taking at Lake Somerset in Somerset Pa. overlooking the spillway.
I remebered some braces like that and done a search and found the one I remembered. Is this the one you were thinking about? It seems like a good simple idea.
https://www.tinboats.net/forum/viewtopic.php?f=3&t=10228&p=108477&hilit=2x6#p108477
I tried calling attwood, but I didn't get an answer. When you find out anything please let us know. It will be useful when I get my livewell installed.
Did you check there website to see if you could find anything? https://www.attwoodmarine.com/
There pumps don't have a check valve so an overflow may be needed.