I suspect the phone at the Butler County courthouse is already ringing. If anyone is in the area, the address follows for a little public-records digging. Don't be surprised, though, if older records are in some sort of limited-access storage facility offsite. This could take the better part of a day to run down.
Here' 'tis:
Butler County Courhouse
205 West Central
El Dorado, KS 67042
Phone: (316) 322-4300