Okay this is what I know about the Jim Kern Swap.  
Cole Camp is southeast of Sedalia on Hwy 52 or 54, can't remember.  This is a Thrusday, Friday, Saturday and Sunday Swap.  I think they are gearing it towards imitating the Jacob's Cave swap.  I think it is 5 dollars per car to swap/sell/look and 5 dollars to camp (in the rough).  
I have never been to the swap before, but the advertisements I have seen are very professional, which makes me think it is pretty big.  I know they have had it the past three years, I just have not been able to make it.
I will try and find out more info, anyone interested????
Sheila