I played little league baseball in Farnhamville, Iowa back in the early 80s. When I saw this car I had to put one on my layout. Farnhamville is a town in the flattest part of Iowa, it has about 150 residents but does have a huge cooperative grain elevator.
I have four Farnhamville hoppers. Three are MDC and one is Athearn. The Athearn is part of a ten car set (I think it was 10) of Midwestern Grain Co-op hoppers that were released as Walthers kits. I have several of the cars. Another pink one is the Albert City from that set. I have a couple of Klemme hoppers but without looking I am not sure if they are MDC or Athearn.
I have a pink Klemme that I bought at a flea market. My wife remembers seeing them as a kid in Northwest, IA so she enjoys seeing it on my layout.
I'd guess its an Athearn.
Ralph
I plan to take a trip down to the BNSF yard here in Council Bluffs as there is always a long string of grain hoppers lined up to go south to Kansas City. I have spotted several Klemme pink cars and will look for some of the others. Hopefully I'll remember to take the camera along!!