Checking the legacy.com link posted by RSwank, it states that Pansch's son Dennis and his wife Jane still live (at that time at least) in Correll Minnesota.
Their names come up in the white pages directory:
https://www.whitepages.com/name/Pans...hedName=Pansch
Is that who you tried to snail mail?
(I live in Minnesota, but I'm about a 5-hour drive NE of Correll, so not likely to be able to get down there anytime soon.)