Reed Cary summarizes what we (don't) know, in a posting on the CWML e-mail list: 'Sometime after the Kaiser aquisition of Willys-Overland (and perhaps after the using up of W-O frames) some CJ-3B frames were stamped. All they knew was that it was an 'MB' Jeep, so they gave it an 'MB' VIN prefix.Some CJ-3Bs carry various numbers stamped into the frame, which appear to be related to the serial number (VIN) as well as perhaps to parts identification. The VIN number on the title is likely a number assigned by a bureau of motor vehicles when they could not find a serial number when they needed to assign a title. Your Jeep was probably built in late 1942 and the plate is very likely the original serial number. (It is close to a model year split - so a number of things could have caused the difference). My '48 truck serial number says it should be a '49 - but it's unmistakably a '48. Although 'everyone knows' that the serial number was stamped on the frame, yours was a metal plate. This is one of the first Jeep lessons you will have. (Compare this to 1941 when only about 8,400 units were built and you get an impression of how serious our war effort was back then!) The first MB serial number in '99, the last was 200022 a build of 91,424 units. But, the 'MB1959xx' corresponds to an MB built in late 1942. Your plate seems to be stamped 'MB195956', the last 5 is blown away a little by a weld and I'm kind of guessing at the '6'. If you google MB Jeep Serial numbers, you will find a link back to a KWAS listing of serial numbers by year and type. Good Luck, and post pictures and stories for us. Since this is the 75th Anniversary of the Jeep, there is a lot of interest on the old MB and GPW's. You can always say 'As far as we have been able to find out.' and tell the story your way after that. Working against that is the MB1# tag which, it that were the serial number, puts it into a 100-thousand serial range. Your Jeep could be an MB if the date is correct and if, by some chance the title is correct, the MB# could be the serial number. I'm not a little Jeep person, but that seems to be the general vicinity of where you have a small riveted tag. on the upper left chassis rail between the gusset and the bumper.'. Willys MB serial numbers were supposedly stamped (not a plate) '. If your Jeep really is a '42, and if it is a Willys, it probably is a model MB (Fords were GPW's). We have always learned to take what titles say as suspicious, but in your case the title may have some useful information.

The first 60 pages or so are an encyclopedia of Jeepology. If you work around old Jeeps long enough, you realize one of the most common things you hear is 'Well I never saw THAT before.'

Willys Jeep Serial Number Location