With a serial number of 455948, this was within the last 5000 MBs produced.  The highest MB serial number that I know of is 459851 (http://wwiijeepparts.com/Archives/JeepSerialNumber.html).

“This is a 1946  mb willys i just picked up the guy I got it from have known for 10 years and been trying to get it since I met him he has sold. His property and is moving to Arizona so he had to get rid of it I traded a chrystler le baron convertible for it it has some rust and has been in Colorado for at least 20years he got it from his father he said it ran when he parked it but the motor is know seised up think it just got some condensation in the motor from sitting and rusted flathead motor and the guy said the motor ran great before he parked it  not sure why windshield is not split must have been replaced title says mb and glovebox placards say mb all placards there thanks rpm”