Yes, those are the only DWELLO / BILLMEYER burials in the respective cemeteries.
I don't know whether the Iowa Recorder still exists (you could search for information at google.com or post a new query to the message board.
In the meantime, yes, there are ways of finding out more about P.N. DWELLO. Do you subscribe to any of the genealogy databases? In addition to census and vital record information, many historic newspapers are now available. For example, membership in the Godfrey Memorial Library ($35/year) gives you Heritage Quest, Pro Quest, and many other resources.