I have been following the current thread - hot topic - on ILS on S&W revolvers. Something caught my eye - reference to internal locks on Ruger revolvers. Guess I have been away in a monastery - this is the first I have heard of Ruger internal locks. So , after church I need to dig the SP101 out of the safe , remove the wooden Hogues , and check it out. What am I looking for? Do all models have the ILS?