The following came from the folks in the Southern Regional Office of Indiana Landmarks:
We had some repair work done a couple years ago on a barn that Landmarks owns outside Georgetown, and we used an Amish crew out of Odon, Indiana. The main fellow was Harvey Graber, 812/486-9800. Taylor Brothers Construction out of Columbus, Indiana (812/379-9547) also has quite a bit of experience with historic barns.
Southern Regional Office
I would also add Herschel Brichto (Vevay) 812/569-6500 and Josh Stiles from Perry County (812-788-0591). Rick Collins from Tillium Dell out of Illinois may also be a possibility (309-221-8020).