Can you help identify this sail with a rat on it?

Thread starter #1
My in-laws found this sail on the side of the road many years ago, and stored it in their basement. They thought it might fit my sunfish, but it is definitely not for a sunfish. It's much taller and narrower. I looked through the insignia listings that I could find by Google, but I haven't found a match.
Thread starter #3
I'm guessing the rat must not be a class designation, perhaps it is the marking of a club or something. Here are a few more pictures. If anyone can help identify it, please speak up. I'd hate to have to throw it out just because I can't find someone who can use it!
The first photo shows it laid out on a trailer that is about 7x14 feet, so I'd say the overall length/luff of the sail is around 10-12 feet and the foot looks to be about 7-8 feet. There are a couple of short battens along the leech, perhaps a foot or so long. One is visible in the first photo in the blue section of the sail, and the other in the orange section.