Neither pinned, nor recessed, this Model 19 comes near the end of the model run. An "AJU" series serial number puts it somewhere in 1985 in terms of production date.
The pistol belonged to my uncle, and was sold to me by his son, my cousin who is a "Glock Guy," at a very advantageous price. I changed out the really chunky target grips with a nicely book-matched contemporary "targets" from Smith & Wesson; the new grips fit my hands much better. The revolver was shot very little and is in nearly new condition.
Enjoy.