Bingo! Well found, Ron. It seems to answer all the questions - especially if some leniency was common in the decision which wounds were 'equally prejudicial to his habit of body with the loss of a limb'. Nice that it began on Christmas Day (which was, I think, one of the quarter days, regularly used for such financial transactions), and though I don't think that the amounts show much Christmas generosity, they aren't that bad, if the recipient could continue to serve and have them as a addition to his regular pay. (Pity they didn't have a double rate for those incapacitated from service who had only lost one part - but perhaps they were granted two in practise sometimes for other wounds).
Does anyone know of a first hand account of an officer being examined by the Army Medical Board?