Not often we see a herd of that many fine KKs ( and giant Cricket ! ) Interesting how they are very close in size even though presumably made by different people at different times. That's a great collection.
The ? looks to me to be of sandstone, if so it's an ancient sanding block.
its awesome to see that many kerrvilles in one picture. The first Kerrville I ever saw was when my then boyfriend, now husband Eddy found one while walking a creek by Fort Mckavrick (forgot how to spell it darn) many years ago. I was new to hunting and I remember thinking that he made up the name LOL.