I had done alittle research on the men who were responsible for killing Bill Wilson, I would love to see the court records you have I have a few articles on the case, one out of Clarksville, Clarksville Red River County, Texas April 17, 1869, in this artilce it does not name the victim, also an article out of the Texas News Fannin Co., Texas Saturday March 20, 1869, in this article no names of victim or murders, I also have an article written years later don't know what paper it came out of nor the date as it was given to me, and another out of the Sherman Daily Democrat, again no dates it too was given to me. They are rather large, scanning is impossible and the way some of them were copied story runs off to another page then another. A couple of them I can scan if you are interested please contact me at email@example.com
From what I know William O Blackmore rode with W C Quantrill also, under William Anderson he is listed in the Encyclopedia of Quantrill's Guerrillas by Rosemary Lankford. Bill is not listed in there, however any information you have on him being with Quantrill and send to her she will update it.