That's a beauty. I picked one of them up at a show several years ago, and haven't seen one at any subsequent shows since. Definitely a keeper and certainly display-worthy!! Amazing that that was just hanging out in the river!
You should gets some pics of it anyways and see what the insulator guys say. You never know what it could be worth and it might give you enough incentive to try to find the rest of that one and maybe a few more. Swiz