Well, I found out that it was back to the drawing board on my "calibration" with the scintillator probe.  In order to "see" lower energy gammas (like found in a smoke detector element, which is Americium 241), the gain (sensitivity) settings on the probe and meter need to be turned up almost all the way.  On the meter, background count went way up, and I even set the voltage a little higher.  The probe and Ludlum Model 16 now work.  How sensitive is it?  A little more sensitive then the PM1703m.  However, the Ludlum seems to pick up Am 241 better than the PM1703m.  Worth noting, no smoke detectors where harmed in the matching of this meter and probe.