That's some really good shooting!
That grip tape brought back a memory of when I shot my K38 in a police revolver bullseye league in the 70's and 80's. I always had a hard time maintaining a consistent grip cocking the hammer in the rapid fire stage, and wrapping my grip in old-fashion grip tape (tar tape) helped a lot.
Tar tape is a childhood memory for me - we used it on baseball bat grips and repaired our scuffed up baseballs with their seam stitches unraveling with the stuff until they were about 7/8 sized and just a black lump.
Thanks for the memory.
I'll bet your score will go up when you do a load workup for your gun with 148 gr wadcutters.
Looking at a lot of old photos of revolvers used for competition back in the day, grip tape seems common. I don't think I saw anyone using it on the line at the revolver match I attended in November. It might be one of those "lost" tidbits of knowledge that needs to be rediscovered by people. The CMP rules explicitly allow for it so clearly someone was aware when they made up the rules approximately 1.5 years ago.