The 4.2" had the checkered inserts, and you are correct . I did not see those on shopruger. If you just need the inserts, I have a set I took off of my .327. I replaced mine with some stags.
Right now I'm looking for the whole grip including the inserts. I bought my SP-101 used and it has an aftermarket grip. I want the factory grip just to put in the box for the day when my son gets them all. I'll keep your offer in mind in case I find just the rubber. I appreciate your help.