If it's really a 1952, it will be a TO-30. But if you get the serial number (look for a plate on the dash) you can check on this site to know for sure. Also, a TO-30 will have a continental Z129 engine (look for a plate on the engine somewhere).
These old Fergusons will run strong for a long time. But of course it depends on how well its been taken care of, and how well you take care of it.
Most of these tractor came with PTO, although a TO20 or TO30 will not be "live" PTO. You would need to find a TO35 Deluxe for that.
12V is ok, but I have never seen a need to convert. My 6V TO35 started right up in 0°F weather. As long as the cables, battery, generator, and starter are in good shape the 6V system is just as good as 12V. Check to make sure the 12V conversion was done right. Do the lights work?, does the battery charge?, etc.