farmall b

The numbers you posted appear to be CASTING NUMBERS.

Did you look for the ENGINE serial number, STAMPED into the RH front of the block, just below the cylinder head? That will get you CLOSE to the tractor's serial number, with certain exceptions the gurus can explain to you.

Many of the major castings have date codes cast into them. By finding these and decoding them, you will learn when each part was CAST, at the foundry. The parts were cast from perhaps a week or so, to as much as a year before they were MACHINED, then assembled into a tractor.

• IH Board

You can then compare the year of manufacture based on the serial number to the dates on various castings to see if your tractor is likely original, BUT if the seat support with the tag is gone you probably will never know for certain AND what does it matter anyway? It's a nice little tractor even if they had to swap a few parts here and there!