I don't wish to argue the ethical implications of a desertion, my goal is to try to have a better understanding of the circumstances of my ancestor's life at that time.
I have been fortunate to find a historian/author/professor who has much expertise in the history of desertions during this period. I contacted him and he has been kind enough to offer to look over the service records and offer an opinion and further input. I will return and let you all know what he says. I am not posting his information here as I do not have his permission to do so- but will see if I can get his permission to cite him when I return for a follow up.
The main part of this story that puzzles me is that he WAS taken prisoner- and then refused to take the oath repeatedly while at Rock Island. I do not understand why he would do that if he'd deserted and was anxious to stay with his family. But I am applying this century's logic to that of another age, in a situation that was difficult beyond what most people now can fathom.
George- to answer your question, I have no knowledge of a pension or any benefits one way or the other. Many members of the family migrated west (some to the territories later on) after the war and started over. The family was close knit, stubborn and took care of their own, so maybe a pension was never considered for those reasons. I am not sure.