Hi John,
On most but not all early Te series tractors, if you look on the right side of the rear transmission housing, just behind flange where the gearbox joins, you will find the date of manufacture cast in, vertically. It will consist of a number for the day then the month and the year is shown just as a single number. Typically similar to this "22 10 3" which would translate to 22nd October, 1953. On a lot , but then again, not all engines have the date cast into the block just above and behind the generator, in a similar fashion.
The air cleaner would indicate an early model. Was it originally six volt? The way to tell the difference is the casting in the bell housing to cover the starter drive is short on the 6 volts system and longer on the 12 volt as it pulls the Bendix drive in from the rear of the flywheel.
Hope this doesn't confuse the issue for you.
Cheers, Steve.