Did he have an address in Marshalltown? I think that may be him. In the Soldiers and Sailors Sytem there is a W C Kimberly from the 1st Iowa Cav. His name is written in a 1907 copy of The Lyon Campaign by Ware. He wrote it was a gift from his daughter Anna Maude.
I could scan it if you are interested, maybe you can decipher it.
Thanks,

Frank

There's nothing about Marshalltown in the Rosters. Just that he lived in Newton when he joined.
Clark