Jane, his wife, seems to have received her initial Allotment payment around 9/3/1813 and received a total of £14:18s:8d which equalled the precise amount for 32 monthly payments. Those payments ceased when Orlando left the Marines and he began to receive his pension in four payments each year of £2:5s at 3 monthly intervals. As the younger one in the Army was supposedly 21yrs when he joined the Royal Scots and Orlando the Marine was recorded as being 38 yrs when he went on the Pension list in 1851, they can not relate to the same person. We ae looking backwards for 200+ years and unfortunately we will be unlikely to find proof one way or the other beyond reasonable doubt, as required for conviction in a criminal case. We have to make do with proof on the balance of probability, which is the required standard of proof in civil cases.
I found your search and dilemma quite challenging and my best wishes for your satisfactory conclusion.