Lucky you, Tango, your back in a big way! The bike may have suffered a broken drive chain and a hole in the case, the dealer would have replaced it under warranty. Sometimes they stamped the engine number, obviously not on yours. Replacement cases do not appear to be sandcast, too bad, big hit to the value. But, there is still a lot of value to it, someone may mate a numbers correct engine to that frame and bingo, big bucks. Does it have the wrinkle gas tank? I believe the no number pipes are correct for that bike. I'm no Sandy expert, Mark and Greggo are and I'm sure they can help you.