from what I have read, the clones are those that have the angles on the outer edges of the transom. they go by many different names, but I think I read in Canada they were still called sidewinder but they are different than the CA. winders. I dont really know why the lo pros are called clones or splashes of the original lo pro sidewinder because they really are nothing alike. although I have never seen a great pic of the bottom of a splash, I would like to see a pic of the bottom of some.
sidewinder h.i.n. (hull id #'s) are on the right side of the transom, if your boat has been painted they could have been filled in. mine were but when I sanded down to them I was able to learn alot about my boat on the sidewinder site and by Dan Milford, a guy that has been documenting them for years.another guy that knows a bunch about them is "old rigger" here on the boards. this topic has came around in the past on this site.