Just a quick question about bumps on the blade and tooth side at the shoulder of a Best key. Under the Best logo it says "patented by Kaba," next to the numbers 3902, on the reverse side it has a 6 digit number cleanly stamped on it, then a few letters and numbers that appear to be hand done, as in not perfectly aligned. Also it is stamped KB near the shoulder. The KB looks like a blank number. I've done some research and come accross some talk about there being additional bumps on some higher sercurity locks that engage some additional ring in a core. The lock this fits has a rounded out (convex?) keyway that protrudes out. I'm guessing this key/ lock system is what I read about? If so how does this work? I usually take apart a lock to see it's inner workings but this one's a mystery. We are gutting out a building and the owners gave us a master key to facilitate our work.
BTW, the building is full of Best cores that are going to get thrown in the dumpster. Are they worth anything to anyone? I have tens of them that I practice on and would be happy to help some other hobbists out. In the past I've found the control key and recovered many cores before they met a wasteful disposal.
Thanks
Mike