I seated the cams more soundly to the rods, but that does not to have helped. I still get times when the left will just barely trip the sear. The three position safety is not precisely set when the top lever moves. Sometimes it says safe, and is so. Other times it says safe, but it must be just slightly off; off enough to let the trigger move slightly.
What I am not familiar enough with on Smith's are the types of behavior relative to how tight the screws are: specifically the tang and side plate screws. If the side plate screw is overly tight, both sears can be tripped from just the front trigger.
Should have checked all of this more thoroughly before acquiring the gun.
