the number on the hood sides is the USA registration number, basically the VIN... That number will be on the dash tag , and if I recall correctly, should start with "02" if an ex-Army jeep... Main Organization (Div, BN, Regt, etc) goes on the passenger-side front bumper, driver side rear .. Unit (Company etc) and individual truck number (such as B-11) goes on driver-side front bumper, passenger side rear .. Marines, Navy, AF etc used a slightly different method..
There is a way to sometimes discover the assigned unit of a vehicle via the USA number, but it doesn't work for all.. There is a database on this website somewhere but I do not know if it covers jeeps.. I am guessing "yours" has no bumper numbers however sometimes one can see an outline underneath the paint, or after the paint is sanded off
My professional advice on the M151 as a former army licensing administrator/road-tester , try not to slide sideways anywhere, don't take turns fast nor sharp, nor stop hard on blacktop, among other things .. I have been to a few too many M151 mishaps in the 70's-80's.. And if you feel the "lean" in a corner, it is too late and you're well on the way to a headache or worse.. The M151A2 is more stable than the earlier A1 and base models, but still was not perfect and can be dangerous even deadly in uneducated hands.. We spent over a week in MTOC just on the M151 and its quirks before moving on to the big trucks.
I was always impressed with the M151's sure-footed straight up/straight down hill climbing ability, but that was about it ... PS, had to drive a ragtop mutt with no heater 3 hours through a sudden snowstorm on my way back from a tank company's location. Was the only vehicle out there except for an occasional oncoming truck. With wind gusts blowing me all over the road in places, I thought for sure the day would end with it stuck in a ditch or a drift, or blown head-on into something else .. No radio, no heat, nothing but the window scraper I grabbed from my truck .. Glad to see "yours" has tires that will do just fine no matter what. We have a saying about military non-directional tires ; they can take you in every direction you don't want to go