Found the following error chip listed on eBay. It is a $5 Central Palace, Central City, CO chip with double HS on one side and no HS on reverse.
I contacted the seller and she agreed to let me use scans. Cannot afford the chip, but can at least submit to chipguide.com so other collectors have reference to it and know of it's existance. Will also submit scans to cochips.com and David Niver so it can be included in their next reference guide edition.