It took me a few years, but I finally got all three of the mass produced barrel lengths available for the Model 19 from 1967 until production ceased on the Model 19 in 1999. The 6" and 4" are both a 19-3 and the 2.5" is a 19-4. All three are pinned and recessed. Many more variants out there, but this is what I wanted to complete first. You know it wasn't as easy as some people would have you believe. The P&R Smiths aren't as common as they used to be and I believe that might go double for the P&R Model 19 examples.