About four of the tractors are John Deere, a couple of "A"s and a couple of "D"s. This one is a model A, serial number 266417. This number tells us that it was a nonexistent tractor. It seems that the "A"'s serial number range began in 1934 with 410000 and that it was a row crop tractor. This is not. Strange. I'm quite sure I've seen other "A"s on the prairies with this (field tractor - not row crop) configuration.
This is actually an "AO", an orchard variant of the "AR" field tractor with no exhaust stack for better clearance under the low hanging branches. The name plate apparently doesn't differentiate among the variants, stating that they are all "A"s. So that means that this "AO", serial number 266417, was built in 1946.
The A was John Deere's first true row-crop tractor, replacing the GP. The tractors appearance was changed in 1939 with the "styled" look. In 1940, with serial number 488000, the engine was increased from 309 ci to 321 ci. In 1941, with serial number 499000, the transmission was changed from four forward speeds to six. There were several variants of the A. The A was the row-crop model. The AR was a standard (or fixed) tread model.
The AO was an orchard model, with no exhaust stack and shielded fenders. There was also the AI industrial model, the AN with narrow front, the AW wide front, and the high-crop ANH and AWH. The model A was the first Deere tractor to come from the factory with rubber tires. The "slant dash" A was produced between 1939 and 1947. It was an A with the electric start option; a special hood piece was used to cover the battery. In 1947 (serial number 584000), the battery was moved under the seat.
From Tractor Data