M37 history questions

[Saltydog]

I am a new M37 owner and new forum member. I am a US citizen based in Thailand. I recently bought a M37 here in Thailand. It was one of 52 vehicles that were given to the Thai military for DRMO by the US military. The Thai military auctioned off the vehicles and I bought the truck from the auction winner. I have all of the auction paperwork but since it was a 52 vehicle block, I don't have any vehicle specific information. I am trying to pin down the year of the truck so I can start buying parts in order to restore it. The serial number on the frame is L-245A-5527. When I put this number in the serial number finder on this site it doesn't come up with anything, but if I put the serial number as follows L245--5527 it comes up with a 1959 produced truck. Is this accurate? What is the difference between the 245A and 245 engines if anything? Is this perhaps a Canadian version? The truck is in great shape and I have what I believe to be all the original equipment except for the transmission. The previous owner removed the engine and put a new one in it with a new transmission. He kept the original engine and I have that as well. I took it apart and it looks like it is in good condition. I still need to take measurements and check though. That is another question. I have the rebuild manuals but they are referring to the 245 engine not the 245A engine. Are the rebuild specifications the same between the 245 and 245A engines? I have pictures of the frame number and engine casting numbers. I would upload them but can't figure out how to do it on this forum. I can email them if needed. I will list them here for the time being:
Frame: L-245A-5527
Engine Casting: 1484929-21
Engine head(stamped on): T245A-2057I8
Engine head(casting number): 1320136-2
There are also the letters D T cast on the head and some symbols cast on the block. Anyone who can help me with identifying this truck please respond.

[m-37Bruce]

Your vehicle id # is located on the frame, drivers side, just behind the steering box, this should match the serial number on your glove box data plate.