I caught that about Matilda. Also looked over the probate records, and it did mention several different counties and substantial acreage, so perhaps he was a substantial property owner in the state which would explain his huge household in 1860 perhaps.
The probate is definitely the same Martin, the age in the census record matches up with the age that Billy found too, so odds are, this is the right Martin. I will check fold3 when I get a chance and see what I can find, as there seems to be a substantial amount of documents on Martin. Also, sometimes the muster out date is a date of death or severe injury which would explain the possible DOD of 1864. At that time in the war, most men would not be released from service unless they were injured. :)