These are really cheap right now at CDNN, so I bought a couple and hacked them up to see if I could make them sweet. I could, it turns out.
First set, I left a pinky perch but clipped the bottom to shorten it a hair.
Second set, I went full boot, flush with the bottom of the grip frame.
On both of them, I very slightly recontoured the backstrap, taking a bit of the curve out of the upper middle portion. Just like fractions of a mm, but enough to make a difference. Did slightly too much on the lower portion of the semi-boot, which was the first trial. You can see in the photo that the uncheckered portion is slightly thinner. Then went around cleaning up the edges and making the halves match each other. There's a bit of a gap that I plan to fill with black urethane, once I confirm they are worth putting more time into.
My understanding is it's something like 30 year old rubber at this point, so it starts with Dawn, warm water and a toothbrush to get the slimy goo of plasticizers off the outside. Once that's done, the rubber cuts/grinds/sands quite easily, leaving a good, smooth finish from 220 grit paper. It's harder and less grippy material than the Hogue or Taurus grips, although still grippier than would minimize risk of printing.
So far, I've only shot the full boot version, but it's thoroughly decent. I like it the best of any J frame grip I've tried so far, which includes the Hogue Centennial and the Taurus. The finger grooves are fairly large and fit my XXXL hands nicely. It fills in the back strap and is just straight enough to work well for me. The reach is increased so it actually works, and I have a hair more space to fit my thumbs. It feels more controllable to me than the Hogue, which was longer, thicker and stickier; substantially worse for concealment. I suspect I'll end up with full boot as the full time solution on both my Js, and likely any future Js I might buy. Already hoarded what will probably be more than a lifetime supply of the base grips, because they are really cheap right now at CDNN.
I'm thinking about making some K-frame grips that are as close to this same profile as will work. It works really well for how small it is.
Now I just need to figure out why the Precision Delta wadcutters are sticking to the barrel, the throats and even the inside of the cases.
The J is a police trade 640-1 that's ridiculously smooth. I haven't had the side plate off yet. Touched up the sights with fresh white/orange on the front and Sharpie on the rear, and it works well for me.