I know this is a somewhat tardy reply...but. a USAF Jeep would have been marked year purchased then a "K", not "B".
B was the code for a commercial vehicle...like a staff car or pickup truck.
K was the code for a general purpose military type...which the M38A1 was.
Now later on, after M38A1 production had ended, the Military bought a few CJ-5, 7 and even 8s.
Those would have been "B" vehicles.
So my 1955 would have been 55K1234.
A CJ-8 bought in 1981 would have been 81B1234.
And at the risk of getting too detailed...
In doing research for my own USAF paint scheme, I have come across photos and restorations with either "U.S.A.F" or "U.S. Air Force" on the hood with a serial number below.
the serial can be either the 52 (or whatever year bought) K1234
or something like..."A-123456".
I assume the A stands for Air Force, the rest of the numbers are It's Army serial.
Why am Army Serial on a AF Jeep?
Because the Army contracted all M38A1 production.
It then released (sold?) some of them to the Air Force.
Do an online search for USAF Jeeps.
Not many period photos out there...but there are a bunch of photos of later restorations...with varying degrees of correctness.
Also, watch the shade of Strata Blue paint. Many are far too light/bright.