The serial number listed (MD43849) would suggest an M-38A1, but maybe it’s a misprint and should be MB43849?

https://stlouis.craigslist.org/cto/d/washington-1942-willys-jeep-mb/6906000826.html

“1942 Willys Jeep MB
Original Navy Jeep with frame support for machine gun, mostly restored with a few exceptions as original for dependability and authenticity. For example, has Warn front lockout hubs.
All body parts—headlights, outside handles, axe mounting, brake and clutch pedals, fuel can and spare tire mount, etc.—and frame steam-cleaned and painted separately front and back sides with at least two coats quality WWII green paint, body undercoated. Body mounted on frame with felt pads.

Five new tires and tubes
Top bows are included but not installed.
6 Volt system. New 8-volt battery, seal beam headlights, front and rear blackout lights, dash night lights. New 6-volt heavy gauge wiring harness heavy gauge, new ignition switch, Army blackout light switch, panel switch. Circuit breakers replaced with fuses.
New horn.
Professional rebuilt engine. New pistons, rings, valves, valve guides and seats for unleaded fuel, head planed, crankshaft turned 0.03” over, cylinders 0.030” oversize, new oil pump, crankshaft bearings, timing chain and sprockets. New fuel pump, copper lines, and after-market stainless steel 15-gallon fuel tank.
New clutch, resurfaced pressure plate.
New steering knuckle oil seals.
New ammeter, oil pressure, temperature gauges.
Rebuilt hand brake, new brake liner.
New brake shoes, wheel cylinders, master cylinder, steel brake lines and hoses. Two of four U-Joints new. New shock absorbers.
Rebuilt carburetor, starter, and generator. Oversize 02 battery/starter cables
New 1 1/2” exhaust system including muffler.
Radiator rebuilt, new hoses, 190 degree thermostat, rebuilt.water pump.
Odometer below 58,000 miles, believed to be accurate. Has been run approx. 50 miles since restoration and engine rebuilt.
New metal seat frames and Beachwood Canvas seat cushions.
Included: TM-10-1513 Maintenance Manual, TM-10-1186 ,Master Parts List Manual, TM9-804 Operation Manual.
New shovel, axe, all vehicle straps and hood welts.