I sighted the LDS film of the marriage certificate for Michell/Kellow. I had hoped to see his signature but it was signed with a cross ' his mark '. Also the witnesses were officials where I expected to see a parent. Catherine had signed her name. In various sites he is referred as Sampson or Samuel and Kellow, Kelly or Kelley. In all cases the date in 1807 and Catherine Michell are constant
