Is there a reliable way to tell if a Schon is Runde era? I have a line on one that the guy claims to be about 25 years old. It's in very good condition with 4 black ebony points (no veneers), an ebony butt plate with 4 small maple(?) windows with split diamonds in each, and a black linen wrap. The forearm appears to be maple and stained brown. Sorry no pics.