help me id this speedo

cleaning out my shed of old parts came across this old speedo. any clue what its from? wanna buy it ;) ? how much do you think it should start on ebay for?
http://s270.photobucket.com/albums/jj102/blkmonday/?action=view&current=speedo.jpg

Go to www.hemmings.com and post the picture on the forum . There should be someone there with an answer - good luck !