I once lost the contact cap for my D850 grip. I played the google guessing game until I finally got the right combination of words and found a replacement via ebay. It took some time. This included searching for both Nikon and 3rd party grips, as that part had a reasonable chance of being the same. On the "if it happened once..." theory, I bought 3 of them. It may not work for this part, but I thought it worth suggesting.