The honesty article
Post a Model A serial number in any Deere forum — say 577582 — and someone will tell you it is a 1946, someone else a 1947, and both will paste a table to prove it. They are not arguing about the tractor. They are arguing about which of Deere's two lists to trust, usually without knowing there are two.
Deere's first published beginning-serial list was built on its fiscal year (November 1 to October 31). On that list, the 1947 model A begins at 578516, and the 1946 begins at 558817. Serial 577582 falls short of 578516 — so the fiscal list calls it a 1946.
That list has a worse problem than its calendar: the original printing put 588817 as the first 1946 number — out of sequence, higher than the 1947 start. Later copyists "fixed" the obvious typo by changing it to 558817. Both numbers are wrong; the error has simply been photocopied across the internet for years, including onto parts-dealer charts still live today.
Deere later revised the beginning serials to the production (model) year, and that revision is the one supported by Deere's own Serial Number Registers — the factory records researched by J.R. Hobbs and published through Green Magazine. On this list the 1947 A begins at 569610 and 1948 at 587349. Serial 577582 sits between them: a 1947.
577582 is a 1947 Model A — an early-styled one, since the pressed-steel frame begins at 584000. TractorYearCheck decodes every Deere on the production-year list, and any result the fiscal-year list would date differently carries a disclosure saying so. A decoder that hides the disagreement is not neutral; it is just quietly picking a side.
Deere's model years did not start on January 1, and they did not even start on a consistent month: across the two-cylinder era the business year began in November, then July, then November again. A tractor built in the autumn could be warehoused and shipped months later — the registers show tractors with warehouse dates in a different calendar year from their model year. Any single-date list is a simplification; the honest move is to name the convention, which is what the production-year list does.
Try it: decode a Deere serial and watch for the disclosure box on 1940s A results.
The decoder gives you the year. The kit gives you the rest of the check before money changes hands: serial-verification worksheets, the two-numbers check that catches swapped engines, year-split parts traps, and an inspection checklist for each family.
Included in the $39 Buyer's Check Kit