No, not a preform. I agree with T-rex. I have seen the bottom style many times in several collections. it is a knife/scraper. Called an Ovoid Blade (some simular types with a hump are sometimes called a "turtle-back= scraper). I have seen them in several materials and from different ages. Even one that looked paleo and crude. It is a great tool for a man or woman's pouch. Thinner than a good Celt and has several good working edges for several uses. I saw one with a thin tip for punching holes also.The smallest types are nickel and dime size "Thumbnail Scrapers". I have three of the tiny "Thumb-Nail" ones in three colors of flint. Sweet finds all around!!!
~Z~ (formally Zeawolf now useing the nickname Coalfire)