That they are!

Except for the darker (and not as pretty as yours), smooth banana grips on mine,it could be the twin of your blue RB 34-1. It came with checkered banana grips, but I much prefered the smooth.

I also have a M prefix SB, but the smooth SB targets just overwhelmed that snubby, but look perfect on that 4" 34 of yours. The PC Magnas that came with it are a good size and fit for my hands, but would really like smooth ones. Altamont has them, but of course they are "Temporarily Unavailable". Did S&W ever offer the PC Magna's in a smooth version?

One weird thing I noticed when I first got the SB targets was, the factory SB PC Magna's fit almost perfectly in the inletting of the smooth SB Targets. So, you have the size of the PC Magnas, plus the thickness of the targets. A real handful of grip!

Rob