This may not be the right place but I just bought a very nice Winchester M70 Sporter Varmint in .223 and it has a Bushnell ScopeChief VI already on it. This scope is a 4-12x40 AO BDC (Bullet Drop Compensator) that is in excellent condition. This scope has been out of production for years and this is my question. Does anyone know where I can find an original BDC knob for this scope? I would like to use all the features of this scope. All it has is the dust cap on it right now. Thanks, David. email@example.com I have tried all the google, bing searches and have come up empty handed.